VOLKSWAGEN BORA VARIANT 1999 (01) PDF Document

This information is intended to help you form an opinion as unequivocally and accurately as possible in the event of tyre damage and related complaints.

Tyres are hi-tech products that are optimally adapted to the operating conditions of modern vehicles. As with all highly developed technical products, tyres require proper care, maintenance and service. This is essential to ensure safety, performance and comfort for the entire service life of the tyre. Tyres are constantly being further developed. Quality tyres are the result of modern design methods and production processes, as well as continuous quality checks. All tyres that are recommended by VOLKSWAGEN have been tested by the technical development department and have been designed specifically for each model in collaboration with the tyre manufacturers. VOLKSWAGEN therefore recommends fitting only the recommended tyre makes when renewing tyres.

Vehicle safety has the top priority. With regard to the various operating conditions such as:

• differing speed ranges,

• winter and summer use and

• wet and dry roads,

the optimal compromise for vehicle safety must be found. Every tyre is subjected to a wide range of different driving conditions over its entire service life. It is therefore important that the basic requirements for ensuring optimal tyre performance are met. Proper adjustment of the axle geometry during wheel alignment is an important prerequisite for ensuring the optimum service life of the tyre. Therefore, wheel alignment must always be within the specified tolerance range.

Tyre damage and related problems can have various causes. It is therefore very important to ascertain whether the problem has been caused by the tyre or other components. Normal wear and tear on a tyre will alter its characteristics. Tyre noise and vibration could then be the result. These are indications of wear and do not constitute damage in the sense of a tyre defect. Measures can be taken to at least partly eliminate the symptoms. However, in some cases it may not be possible to eliminate tyre noise completely.

The manufacturer is issued with a general operating permit (GTA in accordance with § 20 StVZO (German road traffic and licensing regulations) and EU operating permit) for the overall vehicle with all parts for specific conversions.

Conversions of wheels and tyres can only be carried out under certain conditions. When doing this, the following points must be observed:

• If the size of wheel and tyre, with an indication of the load index and the speed symbol, is included in the vehicle GTA and EU operating permit/type approval, this wheel and tyre combination can be fitted on the vehicle without any problem.

It is not necessary for the wheel and tyre combination specified in the registration certificate part I (certificate of registration) to be fitted. All combinations approved in the vehicle GTA or EU operating permit/type approval may be fitted to the vehicle.

• For the conversions recommended by VOLKSWAGEN AG (see attachment for parts certificate) there are no general operating permits in accordance with § 22 StVZO (German road traffic and licensing regulations).

• Unless the wheels and/or tyres are included in the relevant vehicle GTA or EU operating permit/type approval, the vehicle will no longer meet the requirements of the road traffic regulations if converted.

These versions are based on the conditions valid in the European Union and no guarantee can be provided for their completeness. In some cases there are different legislative requirements outside the European Union.

The table included in the attached parts certificate shows the VOLKSWAGEN AG recommended and TÜV NORD Mobilität GmbH & Co. KG tested wheel and tyre combinations on VW vehicles and also the conditions to be observed for fitting. The use of genuine disc-type wheels on a vehicle to which they have not been allocated is not permissible.

The list of possible conversions deals with combinations that meet the requirements of VOLKSWAGEN AG with regards to road handling and road safety. They are the result of practical trials and are therefore recommended by VOLKSWAGEN AG.

• The wheel and tyre combinations and conversions listed in the tables of the individual vehicles refer exclusively to Volkswagen genuine disc-type wheels.

• Approval of wheel and tyre combinations or a change to wheels from the accessories trade is not possible with the parts certificate attached here.

• Tubeless radial tyres may only be fitted to rims with a safety hump feature on the shoulder.

• Tyres with run-flat properties (reinforced side walls) may only be used on disc-type wheels with an extended hump and on vehicles with a tyre pressure monitoring system.

• If the wheel and tyre combinations listed are used, the associated tyre inflation pressures must be adhered to. The tyre inflation pressures for summer tyres can be found on the sticker on the inside of the tank flap or in the tables of the individual vehicles.

• Sufficient clearance to the wheels and tyres at parts of the wheel housing, suspension and braking system is assured if the notes and specifications established in the parts certificate are observed in all operating conditions.

• Unless otherwise stated, snow chains may only be fitted to the drive wheels. On all-wheel drive vehicles, however, only the front wheels may be fitted with snow chains with the exception of the Touareg (rear wheels may also be fitted with snow chains).

For technical reasons some VOLKSWAGEN BORA VARIANT 1999 vehicles require wheel housing extensions (flaps) on the wing or bumper when using certain wheel and tyre combinations.

Please check if there is a requirement to remove the flaps. The information is located in the overview table for the respective vehicle.

Tyres of the „80“ series (e.g. 145/80 R 13 74 S) will replace the „82“ series (e.g. 145/82 R 13 74 S). Lawmakers have stipulated that „82“ series tyres may be replaced by „80“ series tyres without having been entered in the vehicle documents.

The condition for this is that the „80“ series tyres have the same width, be of the same type – cross-ply or radial belted – and have the same or higher load index.

If only „80“ series tyres are entered in the vehicle documents, „82“ series tyres may only be used if an entry has been made in the vehicle documents.

The Plus running gear differs from the basic running gear in the following components:

• Suspension link

• Swivel joint

• Wheel bearing housing

• Anti-roll bar with coupling rod (not on Passat)

• Drive shaft

• Wheel hub

• Brake disc

• Brake caliper

• Wheel

One of the identifying features of the Plus running gear is the connection between the swivel joint and the wheel bearing housing.

The 5 wheel bolts on each wheel are the most visible identifying feature. The Passat VR6 to 09.93 is an exception. From 06.91, this vehicle was produced with 5 wheel bolts, but was gradually equipped with the Plus running gear from 02.92.

The new registration documents are comprised of:

• Registration certificate part I, which replaces the certificate of registration and

• Registration certificate part II, which replaces the vehicle log book.

Registration certificate part I (certificate of registration)

• Contains all vehicle technical data which must be available to register a vehicle in Europe; however, only one wheel/tyre combination approved as standard is specified

• Contains the EU-wide, standardised, alphanumerical codes assigned to the technical data, so that the German registration certificate can be converted without problems into the registration document prescribed in non-member European countries for registration there

• Contains a field for documenting temporary or final immobilisation of the vehicle, and is therefore no longer withdrawn in the event of temporary or final immobilisation

Registration certificate part II (vehicle log book)

• Contains the note that the holder of the registration certificate is not identified as the owner

• Contains only the current and, if applicable, the last vehicle owner; the actual number of previous owners is shown numerically

• Contains only a small percentage of the technical vehicle data

• No longer serves to document temporary vehicle deregistration. The vehicle and body type specified under number 1 in the old vehicle documents will not exist in the future. In the new documents, this will be replaced by standardised EU vehicle classes with body type

Introduction of the new registration documents will lead to barely any changes for the vehicle operator.

Like the old certificate of registration, the registration certificate part I (certificate of registration) must be kept in the vehicle and submitted to responsible persons on request.

It is not necessary for the wheel and tyre combination specified in the registration certificate part I (certificate of registration) to be fitted. All combinations approved according to the general vehicle type approval or EU type approval may be fitted.

The validity of a wheel/tyre combination which deviates from the general vehicle type approval or EU type approval must still be verified via an entry in the registration certificate part I (certificate of registration), an installation certificate based on a part certificate or general type approval for the wheel/tyre combination.

Manufactures of motorized vehicles must apply for an EU operating permit for all class M1 passenger carrying vehicles.

A certificate is produced on the basis of this operating permit – the COC (Certificate of Conformity). This document certifies that the vehicle complies with the EU operating permit (EU type approval) and can be registered in every EU country without an individual type approval. The document will be issued for all vehicles that comply with the EU operating permit.

These vehicles have an EU type plate (black sticker) in the area of the driver’s door, or in the case of older vehicles, in the engine compartment. The COC document has the same value as the registration document and therefore the original should not be carried on the vehicle.

The COC document contains the EU general type approval number and detailed technical information on the vehicle such as emissions classification and all the permitted wheel and tyre combinations.

Passenger cars licensed for road use in Germany need a general type approval for the issue of a vehicle title document. The type approval is issued by the Federal Ministry for Transport in Flensburg following type inspection. This procedure was permitted until 31.12.1997 and, in exceptional cases, even after that.

Other member states of the European Union (EU) have different procedures for issuing a document similar to the German title document. Until 31.12.1997, each member state was entitled to issue its own national type approvals according to its own procedures. Since 1.1.1998, all passenger cars licensed within the European Union must have a type approval corresponding to EU guidelines. Vehicles licensed for road use with single-vehicle approval according to § 21 StVZO in Germany are excepted. This means the same guidelines apply to all vehicle manufacturers. This makes it easier to trade across national borders within the EU.

To determine the vehicle type, you can use two possibilities:

1. possibility

The last page of the vehicle title includes the field „Certified holder of a general type approval/EEC type approval“. Either the general type approval number of the EU type approval number is entered here, assuming it is the original vehicle title document. This is the case only if the vehicle was not deregistered in the past for longer than 12 months.

2. possibility

Check whether the general type approval number or the EU type approval number is entered on the vehicle identification plate.

Example: Continental ContiPremiumContact 2

1. Size code: e.g. 205/55 R 16

2. Position of TWIs (Tread Wear Indicators)

3. Manufacturer (trade name)

4. Construction:

   • Radial – radial cord direction in carcass

   • Tubeless – code for tubeless tyres

5. Load capacity index / speed rating: e.g. 91 (load index) and H (speed rating)

6. Specified direction of rotation/installation for tyre

7. Maximum permissible load: Data for North America

8. Maximum permissible tyre pressure: Data for North America

9. Number of plies in the centre of the tread and in the sidewalls as well as information about the material

10. E number = Approval number: Tyre fulfils European guidelines

11. Manufacturer code / date of manufacture:

    • Identification number for manufacturer’s plant, tyre size and tyre model

    • Tyre ageing / date of manufacture (e.g. 509 <, stands for 199_, last digit is production year; 0100, last 2 digits is production year)

12. DOT – Department of Transportation: Tyre fulfils standards of the Department of Transportation of the United States of America

13. Marking for Brazil

14. Marking for China

15. Country of origin: e.g. manufactured in Germany (Made in Germany)

16. Safety reference for use or fitting of tyre

17. Relative expected service life – abrasion resistance: based on a US standard test

The speed rating (e.g. “T”) following the size of the tyre (e.g. 185/65 R14 14 „T“) indicates the maximum permitted speed (vmax) of the tyre.

The tyres for the vehicle must be selected so that their maximum permitted speed is greater than the maximum speed that the vehicle („based on model“) can attain.

Speed rating / maximum speed

The load rating can be found on the sidewall of the tyre. It provides information about the maximum load that the tyre can bear.

The load rating is included in the size designation of the tyre (e.g. 195/65 R 15 91T). It is indicated on the tyre as a code according to ETRTO. The following table shows the load rating codes used at VW with the corresponding load capacity of the tyres.

If the vehicle has a national type approval, the maximum speed for the vehicle is calculated as follows:

Formula for vehicles with vmax up to 150 km/h

vmax = 1.03 x v + 3.5 km/h

Example: Specified maximum speed v = 145 km/h

vmax = 1.03 x 145 km/h + 3.5 km/h = 152.85 km/h

In this example, a tyre with the speed rating „Q“ or higher must be used.

Formula for vehicles with vmax above 151 km/h

vmax = 1.01 x v + 6.5 km/h

Example: Specified maximum speed v = 163 km/h

vmax = 1.01 x 163 km/h + 6.5 km/h = 171.13 km/h

In this example, a tyre with the speed rating „S“ or higher must be used.

If your vehicle has an EC type approval, the maximum speed for all vehicles is calculated as follows:

vmax = 1.05 x v

Example: Specified maximum speed v = 172 km/h

vmax = 1.05 x 172 km/h 180.60 km/h

In this example, a tyre with the speed rating „T“ or higher must be used.

It is permitted to use tyres with a higher speed rating. The same applies to tyres with a higher load index.

For the letter „v“, enter the maximum speed given in field „T“ of part I or II of the registration document or under number 6 of the vehicle documentation. This calculation is necessary because all vehicles, for technical reasons, achieve different maximum speeds within a legally permitted tolerance.

Undulations are slight wavy irregularities in the tyre sidewall. They run from the bead towards the shoulder of the tyre. The cause is the accumulation of material at the joints of the tyre components.

Undulations have no effect on:

• Safety,

• Service life,

• Handling or

• Other characteristics of the tyre.

Undulations are visible to varying extents. It is not necessary to inspect the tyre or remove it from the rim.

Modern steel belted tyres are constructed with single-ply side walls to save weight. The sidewall components consist of long strips before they are joined together to form a tyre. They must overlap at the joints. Consequently, slight irregularities or waves are created in the area of the overlapping parts. The overlaps are easier to see from the outside due to the single-ply construction.

The conditions for the tyre storage room have to be:

• dark,

• dry,

• cool and

• ventilated

Stored tyres must not come in contact with fuel, oil, grease or chemicals under any circumstances. Otherwise, the material in the tyre will be damaged by chemical reactions which are not always visible. As a result, dangerous situations can occur when the car is driven. Tyre damage occurs only if the tyre is in contact with the chemical for a relatively long time. If a few drops of fuel land on a tyre during a fill up, this is of no concern.

Storage of tyres

Complete wheels

Tyres mounted on wheels can be stored flat, stacked one upon the other. In this case, it is important to ensure that the tyres are clean and dry. The inflation pressure should be increased to a maximum of 3 bar.

Tyres without wheels

Tyres without wheels are best stored standing vertically. If tyres lies stacked for longer periods of time, they will be pressed together with a substantial force. The tyres will then be more difficult to fit, as they do not sit on the bead seats. If tyres are stored standing vertically, it is recommended to turn them every 14 days to avoid flat spots.

Tyres age as a result of physical and chemical processes, which can impair the function of the tyres. Tyres which are stored for longer periods of time harden and become brittle faster than tyres which are constantly in use on a vehicle. Older tyres may develop hairline cracks as a result of ageing. When tyres are in regular use, the constant flexing activates softeners in the rubber, preventing hardening and the development of cracks.

It is therefore important to take into account not only the tread depth, but also the age of spare tyres, stored tyres and tyres which are not permanently in use. The tyre age can be determined from the DOT designation, which includes the production date of the tyre.

Example of a DOT number to 31.12.1999

DOT ….. 509
Stands for 199_
Last digit is production year
Week

In this example, the production date is the 50th week of 1999.

Example of a DOT number from 01.01.2000

DO….. 0100
T
Last 2 digits is production year
Week

In this example, the production date is the 1st week of 2000.

• It is recommended not to use summer and winter tyres which are older than 6 years anymore. The original properties deteriorate due to the aging process. Winter tyres especially lose their adhesion properties.

• When new tyres are fitted, the spare tyre may also be used if it is in flawless condition and is not more than 6 years old. The age of the tyre has a great influence on the high-speed capability of the tyre. It is possible to combine a spare tyre which is several years old with new tyres; however, this can have an adverse influence on car handling.

• Tyres are constantly being further developed, which can lead, for example, to slight changes in the rubber compound, even if the tyres are of the same make, size and tread pattern.

• All VOLKSWAGEN vehicles are factory-fitted with four identical tyres and wheels.

Front-wheel drive vehicles:

• For reasons of safety, tyres of the same make and with the same tread pattern should be mounted on one axle.

Four-wheel drive vehicles:

• Vehicles with four-wheel drive must always be equipped with four wheels with tyres of the same size, construction, tread pattern and make.

Renewing tyres

Tyres must always be renewed when:

• the legal minimum tread depth of 1.6 mm is reached,

• there is visible mechanical damage

As of 01.05.2006, a change to the German road traffic regulations (StVO) came into force which caused the following supplement to be made: “The equipment in motor vehicles has to be adapted to the weather conditions. In particular, this includes suitable tyres and antifreeze in the windscreen washing system.”

Please point out to customers that, since May 1st 2006, they are legally obliged to adapt their vehicle’s equipment, particularly the tyres, to winter weather conditions.

For driving in winter, VOLKSWAGEN recommends that the vehicle be equipped with winter tyres in the sizes recommended in table 2 of the parts certificates.

As a basic rule:

All tyre sizes listed in the vehicle documents can also be used as winter tyres.

The handling characteristics may be affected by the use of winter tyres and the possible change in the dimensions of the wheel and tyre. Therefore, when using winter tyres, you must adapt your speed to the changed handling characteristics and to the road conditions.

To achieve the best possible handling, winter tyres must be fitted on all wheels.

If the vehicle is equipped with rims other than the factory-fitted rims, you must take the following into consideration when you fit winter tyres:

• Wheels and wheel bolts are matched.

• Whenever the wheels are changed, corresponding wheel bolts of the correct length and with the correctly shaped tapered seats are used. The secure fit of the wheels and the functioning of the brakes depends this.

• The suitability of winter tyres with less than 4…5 mm tread depth for winter operation is limited.

• Some countries require winter tyres to have a tread depth of at least 4 mm.

• VOLKSWAGEN recommends that winter tyres be replaced after no more than six years. The special „winter properties“ of these tyres decline with age, regardless of how much they are used.

Vehicles with tyre pressure control

On vehicles with tyre pressure control, the tyre inflation pressure has to be resaved or matched when changing over between summer and winter tyres.

The tyre industry now supplies winter tyres with speed symbol “V”. But only under certain conditions may these tyres be used up to the maximum permitted speed vmax = 240 km/h.

Vehicles with V tyres

Vehicles requiring V tyres according to the vehicle’s title document can use winter tyres with speed symbol V without restriction at speeds up to vmax =240 km/h.

Vehicles with W, Y or ZR tyres:

Under certain circumstances, vehicles requiring W, Y or ZR tyres according to the vehicle’s title document may not be driven at speeds of vmax = 240 km/h.

Why?

V summer tyres and V winter tyres without special identification have 100 % of their maximum load capacity (as specified by their load index „LI“) only up to speeds of 210 km/h.

Speeds above 210 km/h are possible with V winter tyres only if the maximum load of the tyres is not exceeded. The load capacity of the tyres decreases as the speed increases.

The maximum permitted axle load and the maximum achievable speed of some VOLKSWAGEN vehicles are so high that the load capacity of the V tyres is not sufficient for speeds of up to 240 km/h.

Example: Tyre 205/55 R 16 91V

The load index (LI) 91 certifies that this tyre has a load capacity of 615 kg per tyre at up to 210 km/h. At a speed of 240 km/h, this tyre can carry a load of only 560 kg, i.e. the axle load may not exceed 1120 kg.

The Passat Estate V6 4Motion has a permitted axle load of 1150 kg and an achievable maximum speed of 232 km/h. This vehicle may only travel at speeds of up to 230 km/h with V winter tyres.

This applies to all V winter tyres without special markings.

V winter tyres marked XL have a higher load capacity than V winter tyres without this code. XL V winter tyres allow a higher speed, but this does not mean that the top speed of a V tyre is 240 km/h for every VOLKSWAGEN car. The same conditions apply to these tyres as to V winter tyres without a special code.

Tyre pressure for Extra Load V tyres: Extra Load V winter tyres generally require 0.2 bar greater pressure (this does not apply for the Phaeton 2003 >).

The following table shows how fast VOLKSWAGEN cars may drive with V winter tyres, depending on their respective axle load.

Registration regulations in the Federal Republic of Germany

Only when winter tyres are in use may the top speed that a vehicle can achieve be greater than the maximum speed specified by the speed symbol of the tyre. In this case, a label stating the following must be attached:

This label must be clearly visible to the driver!

Winter tyre pressures

The tyre pressure for winter tyres must be 0.2 bar more than the applicable tyre pressure for standard tyres but not more than 3.5 bar.

Reinforced and Extra Load (XL) tyres

Some tyre manufacturers have for some time replaced the designation „Reinforced“ with the designation „Extra Load“. This designation has long been standard in non-European countries. Technically, there is no difference between them. Some tyre manufacturers also use the designation „XL“ for Extra Load tyres. Tyres with the designation „Reinforced“ or „Extra Load (XL)“ are of equal quality.

Snow chains must be fitted to driven wheels only.

On most four-wheel drive vehicles, snow chains may be used only on the front wheels, but on the Touareg, also the rear wheels.

It is not possible to use snow chains with all wheel and tyre combinations. Notes on this can be found in the vehicle tables of the PDF.

If no particular type of snow chain is specified, then small-link chains may be used. These, including the chain fastener, may not protrude more than 15 mm beyond the wheel’s tread and the inner wall.

On some models, only special, small-link chains are possible with certain wheel and tyre combinations. Notes on this can be found in the vehicle tables of the PDF.

The maximum speed permitted by law when driving with snow chains is 50 km/h.

Snow chains should be removed when there is no snow on the road. There is no point in having them on the wheels, as they adversely affect the vehicle’s handling. It causes unnecessary stress on the tyres and above average wear on the chains.

A tyre has to meet numerous requirements.

Different types of tyres meet these requirements to varying degrees. Depending on the conditions in which the tyres are used and on the type of vehicle, some requirements will be more important than others.

H, V, and Z tyres for „high-performance vehicles“ are expected to have good grip on wet and flooded roads. On the other hand, they cannot have such a long mileage expectancy as, for example, tyres with S or T ratings.

Requirements to be met by tyres

A – Wet braking properties
B – Driving comfort
C – Steering accuracy
D – Driving stability
E – Tyre weight
F – Life expectancy
G – Rolling resistance
H – Aquaplaning

The pie chart illustrates to what extent the tyre meets the various requirements. It shows how the proportions of the requirements A to H can be distributed according to the construction of the tyre and the rubber mixture used. Improving one of the characteristics will have a negative effect on one of the others.

Example: An improvement in wet braking properties -A- leads to a reduction in driving comfort -B-, rolling resistance -G- and life expectancy -F-.

The life expectancy of passenger vehicle tyres does not just depend on the rubber composition and design of a tyre. The conditions for use, the vehicle-specific circumstances and driving style have a heavy influence on the service life of a tyre. Modern vehicles with the appropriate engine allow a gentle, economical driving style but also an extremely sporty driving style. A tyre life of 5,000 to 40,000 km or more is possible.

The driving style is the most important factor in determining the service life of a tyre.

Wear behaviour of high-speed tyres

These tyres are designed for use at high speeds. The main objective in the development of this type of tyre is good grip on wet surfaces. The tread compositions do not have the same wear resistance as T and H tyres for lower speeds. The expected life of high-speed tyres is therefore considerably lower under comparable operating conditions.

The following factors influence a tyre’s service life to varying degrees.

Driving style:

• Speed

• Braking

• Acceleration

• Cornering

Maintenance:

• Tyre pressure

Environment:

• Road surface

• Ambient temperature and climate

Vehicle:

• Weight

• Dynamic toe and camber settings

Tyre use:

• Speed range

• Wet or dry

Tyre type:

Winter or summer

I. Steady driving without deceleration or acceleration

Example:

II. Braking (driving style)

Most wear occurs during braking.

Example: Braking from a speed of 50 km/h

III. Acceleration (driving style)

Wheel slip occurring during driving off gently is approximately the same as that occurring during driving at a constant speed of 100 km/h.

Example:

IV. Driving through curves (driving style)

A »sporty« driving style and driving at higher speeds in curves also cause greater wear. In practice, this means that wear is increased 16-fold when the cornering speed is doubled. This is the price that has to be paid for going faster.

Example: Driving through a curve with a radius of 150 m

The vehicle’s weight causes the tyre’s contact patch to flatten. This causes the tread and the entire bracing plies of the tyre continually to be deformed when a tyre is rolling. Low tyre pressure causes greater deformation, resulting in greater warming and increased rolling resistance. This then leads to increased wear and poses a greater safety risk.

Example: Specified standard tyre pressure with cold tyres, according to vehicle load

Excessive tyre pressure will lead to increased wear around the centre of the tyre’s tread and to poor rolling comfort. VOLKSWAGEN recommends always to maintain the tyre pressure specified by the manufacturer.

Demands placed on tyres are becoming ever greater. This is caused by the following factors:

• greater vehicle weight

• high speeds

• high level of vehicle safety

A greater load on the tyre will, of course, lead to an increase in tyre wear.

Driving style has a critical effect on tyre wear. Therefore, worn tyres with an evenly worn tread cannot be replaced under warranty.

• The tread depth is measured in the main tread channels.

• Do not measure at the TWIs (Tread Wear Indicators).

Measure the tread depth in the main tread channel, at the points where the tyre is worn most heavily. The position of the TWIs can be seen at various points on the shoulder of the tyre (Item 2 on the diagram). A „Δ“ or the manufacturer’s „logo“ may appear in the place of „TWI“.

The bars of the TWI have a height of 1.6 mm. This is the minimum tread depth required by German law. Different values may apply in other countries. The TWIs must not be included in the measurement. Tread depth should always be measured at the deepest point of the tread channel.

A – TWIs in the main tread channels
B – Main tread channels with TWIs -arrows

One-sided wear is often caused by driving style, but can be the result of incorrect wheel alignment.

Increased one-sided wear, usually in conjunction with signs of scuffing on the ribs of the tread and in the fine grooves, always occurs when the tyres have been allowed to roll with an extreme tyre slip angle, causing them to »rub« on the road surface.

Driving fast on a stretch of road with lots of curves will cause increased wear, in particular on the outer shoulder. A rounded outer shoulder on the tyre in conjunction with a particularly high degree of wear on the outer tread blocks indicates fast cornering. This wear pattern is influenced by driving style.

To optimise handling, the suspension is set to certain toe and camber values. Increased one-sided wear can be expected if tyres are allowed to roll under conditions which differ from those specified. One-sided wear is especially likely if the toe and camber have not been set correctly. Moreover, there is a greater risk of diagonal washout.

Toe-out or negative toe-in

Distance between the front edges of the wheels -A- is greater than distance between the rear edges of the wheels -B- (-C- = direction of travel).

Toe-in or positive toe

Distance between the front edges of the wheels -A- is less than distance between the rear edges of the wheels -B- (-C- = direction of travel).

To prevent one-sided wear, care must be taken to ensure that the wheel is set within the tolerance specified by the vehicle manufacturer. The most frequent deviation of the wheel alignment is caused by external influences, for example hard contact with the kerbstone when parking. By measuring the axle geometry, you can check whether the wheel alignment is within the specified tolerances or whether it has to be corrected.

Running gear modifications

Using „suspension-lowering kits“ and/or alloy wheels that have not been recommended by VOLKSWAGEN may result in altered wheel positions which deviate from the specified alignment. Even if the axle geometry is correct with the vehicle stationary during wheel alignment, the changed vehicle height and wheel positions can cause the wheel suspension to move differently during operation. Uneven wear is then unavoidable.

Unsuitable use of self-levelling adjustments on pneumatic suspension system

The use of the offroad level is recommended only for driving off-road. Permanent use of the offroad level during normal road operation can lead to increased tyre wear as the height of the wheel position is different to the road level.

The way to prevent one-sided tyre wear is to ensure the wheel alignment is correct on one hand and on the other hand to make sure the vehicle is used only for its intended purpose:

Regular servicing of the vehicle and tyres helps to prevent tyre wear. The following should be noted in particular with regards to this:

• The prescribed minimum tyre inflation pressures must be adhered to.

• Different wear on the front and rear axle in unavoidable depending on the driving style. This condition can be compensated for by swapping over the wheels from front to rear. The ideal opportunity to do this, for example, is during the seasonal change between winter and summer tyres. This change also has a positive side effect in that the tyres can wear down equally, meaning that a completely new set of tyres can be fitted. This prevents the use of tyres with different tread depths on both axles, which can have negative effects on road holding.

• Saw tooth formation is a normal wear pattern, particularly where the driving style is very careful. This can lead to an increase in rolling noise, which generally becomes better as the tread depth becomes less. In the event of light saw tooth formation or if saw tooth formation is just starting, exchange of the wheels between axles is normally sufficient. In cases where saw tooth formation is very pronounced, the wheels have to be changed so their direction of rotation is reversed.

• Some tread patterns may create an impression of premature wear: if winter tyre sipes or channels in the tread are worn down, only compact profile blocks without patterns remain, thus giving the impression of a worn tyre. In this case, the remaining tread depth must be measured in each profile groove. If this is at or below the minimum tread depth, the tyre can continue to be used without restrictions. (In Germany, the minimum is 1.6 mm; it is recommended, and in Austria, required, that winter tyres that are worn down to 4 mm be used only in summer )

This wear pattern is found on the driven wheels of high-performance vehicles that are frequently driven long distances at high speeds.

At high speeds, centrifugal forces cause the tyre diameter to increase more in the middle of the tread than it does at the shoulder. This causes drive forces to be transferred to the road surface from the centre section of the tread. This is reflected in the wear pattern. Effects of this kind can be especially pronounced on wide tyres. It is not possible to counter this wear pattern by reducing the tyre pressure.

For reasons of safety, the tyre pressure must not under any circumstances be reduced below the specified tyre pressure.

A more or less even tread wear pattern can be achieved by rotating the tyres between the driven wheels and non-driven wheels in good time.

Increased tread wear

The typical tread wear pattern of tyres run on the driven wheels of a high-performance vehicle. The increased wear in the centre section of the tread results from the extra load associated with centrifugal forces within the tyre and the transmission of drive forces.

Diagonal washout on a tyre

Diagonal washout runs at an angle of approx. 45° to the circumference. It usually occurs at one point only, but can also occur at several points around the circumference of the tyre. Washout occurs almost exclusively on the tyres on the non-driven wheels, in particular at the rear left. Washout occurs very often on some models, while it poses no problem at all on other models. The effect is intensified by high toe-in values. Toe-in values in the region of the lower tolerance limits of the specified alignment values improve the wear pattern. The most pronounced diagonal washout is often found in the area where the tyre components are joined.

Wheels with positive toe-in roll with a slip angle even straight ahead. This leads to a diagonal strain in the contact patch or foot-print on the tyre/road surface. This wear pattern is intensified when tyre pressure is too low. To avoid such tread wear patterns, the toe-in values of the two rear wheels should be identical and the specified tyre pressures observed.

If washout is detected at an early stage, the wheels should be fitted on the drive axle. Deeper washout cannot be repaired.

Faulty adjustment

If a customer complains of „diagonal wear spots“, the toe adjustment must be examined. If toe-in is correct, the cause of the diagonal washout is very probably the tyre itself. Tyres with diagonal washout caused by incorrect wheel alignment are not covered by warranty.

Tyre noise that can be heard by the human ear is caused by vibrations which are transmitted by the air from the source of the sound to our ears. Of interest here are the noises caused by certain characteristics and effects of the rolling tyre (source of the sound). The cause of the noise is largely dependent on the combination of the road surface and tyres.

The structure and material of the road surface will greatly affect tyre noise. For example, the noise level on a wet road is much higher than on a dry road. The pattern of the tyre tread also has a significant influence on tyre noise. Tyres with transverse grooves at an angle of 90° generate more noise than tyres with grooves running diagonally.

Small tread blocks are unstable. Their highly pronounced deformation agitates the air as the tyres roll. This creates vibrations in the air which cause tyre noise. Wider tyres are louder. They need more tread channels to displace water. When the tyres roll, these tread channels displace the air, also creating vibrations in the air.

Further effects that also influence tyre noise:

• „Tyre vibration“ is the principal cause of tyre noise. It is caused by the columns of air in the tread channels being agitated.

• „Air pumping“ is the compression and expansion of the air caused by the deformation of the tread blocks as the tyre contact patch moves along the road surface.

Useful information regarding tyre noise

Tyre noise is determined primarily by the tyres and the road surface. The roughness, structure and material of the road surface influence tyre noise.

The widths of the tyre and the rim, among other things, influence tyre noise. Due to their larger contact area, wider tyres will cause more tyre noise than narrow tyres, as more air has to be displaced and more „mass“ is agitated to create vibrations. A wider wheel rim will also cause a tyre to have a wider contact patch. The effect on tyre noise is thus very similar to that of a wider tyre. Moreover, the damping characteristics of the tyre may also be adversely affected by the wider wheel rim.

Tyre noise of a vehicle with front-wheel drive is more perceptible in the rear because wind and the engine noise are not as loud there.

Saw-tooth wear is a stepped wear pattern on the individual tread blocks that can cause increased tyre noise. The saw tooth is caused by uneven deformation of the tread blocks in the tyre’s contact patch. Saw-tooth wear is more pronounced on non driven wheels than on driven wheels.

New tyres are more susceptible to saw-tooth wear because of the greater elasticity of the high tread blocks. As the tread depth decreases, the tread blocks become more rigid and the tendency to wear in a saw-tooth pattern decreases.

Appearance of saw tooth

A – Tread block of a new tyre; seen in direction of rotation -arrow 1-; tread blocks are equally high in front and back.
B – Development of saw teeth; seen in the direction of rotation -arrow 1-, tread blocks are higher in front -arrow 2- than in back.
C – Seen in the direction of rotation -arrow 1-, tread blocks show greater wear in the front section of the „saw tooth“ -arrow 3-.

Pronounced saw-tooth wear can lead to customers complaining about tyre noise.

Pronounced saw-tooth wear occurs under the following conditions:

• toe-in values are too high

• tyre pressures are incorrect

• tread is coarse and open

• tyres are fitted on the non-driven axle

• very fast cornering

Non-directional tyres

In the event of saw-tooth wear, the direction of rotation of the tyre must be reversed. If saw-tooth wear is especially pronounced and tyre noise has increased, interchange the tyres diagonally. This will reduce the saw-tooth effect. On front-wheel-drive vehicles, this effect is intensified by the greater wear on the front axle. Tyre noise will be somewhat louder immediately after the tyres have been interchanged but will return to a normal level after about 500…1,000 km have been driven.

Directional tyres

In the event of increased saw-tooth wear on the rear tyres – in particular on front-wheel drive vehicles – interchange the front and rear tyres. In the event of increased saw-tooth wear on the outer edges of the tyres on one axle, turn both tyres around on their rims. The left-hand wheel must then be fitted on the right side of the vehicle and the right-hand wheel on the left side.

Flat spots result from hard braking which causes the wheels to lock so that the rubber is worn off at the contact patch between the tread and the road surface. As the tyres slide over the road surface, friction generates heat, which reduces the tread material’s resistance to wear. Not even the most wear-resistant tread compound can prevent the flat spots caused by extreme braking. Even ABS-controlled brake systems cannot prevent brief locking of the wheels, and thus, minor flat spots.

The degree of such wear depends largely on the vehicle speed, the road surface and the load placed on the wheel. The following examples should make this clear. If a vehicle is braked to a standstill on a dry surface with the wheels locked, the amount of rubber worn from the tyre will cover an area the size of a postcard and will have a thickness of:

• up to 2.0 mm from a speed of 57 km/h (23.8 m braking distance)

• up to 3.3 mm from a speed of 75 km/h (41.8 m braking distance)

• up to 4.8 mm from a speed of 92 km/h (71.6 m braking distance)

Flat spots in tread

Tyres with such damage must no longer be used and must be renewed.

There are numerous causes for vibration. Vibration can be caused by tyre wear, among other things. Tyre wear caused by driving is not always uniform across the entire tread of the tyre. This causes slight imbalances which affect the smooth running of a wheel which was previously exactly balanced. Minor imbalances will not be felt at the steering wheel, but that does not mean that they are not there. They increase wear on the tyre, thus reducing the tyre’s service life.

Recommendation

To ensure

• optimal safety,

• smoothest possible running and

• even wear

throughout a tyre’s service life, VOLKSWAGEN recommends having the wheels and tyres balanced at least twice during the tyre’s service life.

Balancing wheels

Before you start balancing the wheels, the following requirements must be met.

• The tyre pressure must be correct.

• The tyre tread must not show one-sided wear and should be at least 4 mm deep.

• The tyre must not show any signs of damage, for example cuts, piercing, foreign bodies, etc.

• The wheel suspension, steering and steering linkage, including the shock absorbers, must be in perfect condition.

• You must have conducted a road test.

If a customer brings a VOLKSWAGEN BORA VARIANT 1999 to the workshop complaining about „vibration“, a road test is essential prior to balancing the wheels.

• This will give you information about the nature of the vibration.

• You will be able to determine in which speed range the vibration occurs.

– Raise the vehicle on a lifting platform immediately after the road test.

– Mark the positions of the tyres on the vehicle.

– Remove wheels from vehicle.
– Balance wheels.

Clamp wheel into wheel balancing machine

When balancing tyres, remember that cleanliness is absolutely essential, as indeed it is in the case of any other repair work you carry out. Only then can you attain a flawless result! Dirt and rust in the area of the contact surfaces and centre of the wheel distort the result.

– Clean the contact surfaces, the centre of the wheel and the recess on the inside of the wheel before mounting the wheel on the wheel balancer.
– Mount the wheel with tyre on the wheel balancer.

• To clamp the wheel, use e.g. centring system for wheel balancing machines -VAS 5271- .

• This ensures that the wheel is 100% centred and that the wheel will be clamped without damage!

• The wheel cannot be centred 100% with conical clamping elements on the wheel balancing machine.

• A deviation of 0.1 mm from the centre results in an imbalance of 10 grams at the wheel’s rim.

Procedure for balancing wheels and tyres

– Rotate wheel and tyre on wheel balancer.
– Check that the indicator lines on the sidewall of the tyre near the rim flange run evenly.
– Check that the body of the tyre runs evenly while the wheel and tyre are rotating.

If one-sided wear, flat spots from braking or severely washed out spots are apparent, balancing cannot achieve smooth running. In this case, the tyre must be renewed.

– Check the true running of the wheel and tyre. If the wheel and tyre do not run true although there are no flat spots, radial or lateral runout may be the cause.

– Check the wheel for radial or lateral runout.
– If radial and lateral runout are within the specified tolerance, balance the wheel and tyre.

• More than 60 grams of weight per tyre should not be used.

• If more weight is required, you may be able achieve smoother running by match mounting the tyre and rim.

• The wheel balancer display should indicate 0 grams.

• As an alternative to match mounting, you could use the vibration control system -VAS 6230- .

– Bolt the wheel to the vehicle.
– First hand-tighten the lowest wheel bolt to about 30 Nm.
– Then tighten the remaining wheel bolts diagonally to about 30 Nm. This process centres the wheel on the hub.
– Lower vehicle onto its wheels.
– Now use a torque wrench to tighten the wheel bolts diagonally to the specified torque.

Perform road test

– After balancing the wheels and tyres, perform a road test.

Using the vibration control system -VAS 6230- you can perform more functions than just stationary balancing. A special feature of this system is the testing of the radial force of the wheel and tyre while rolling. A roller presses against the wheel with a force of about 635 kg. This simulates the vertical tyre force against the road surface during travel. Radial and lateral runout in the wheel and tyre and differences in the stiffness of the tyre cause the vertical force of the wheel to vary. The -VAS 6230- detects and stores the position of the maximum measured radial force in the tyre. Then the position of the smallest distance between the wheel flange and the centre of the rim is measured.

• Before working with a finish balancer, the mechanic needs to have been instructed by the manufacturer of the balancer.

• To balance the wheels, set the wheels of the driven axle on the sensor platforms (only the front wheels of a front-wheel drive vehicle, all four wheels of a four-wheel drive vehicle).

If you determine a residual imbalance greater than 20 grams when balancing the wheels, you should rotate the mounting position of the wheel on the hub.

– Mark the point at which the imbalance is indicated.
– Unbolt the wheel and rotate its position on the hub so that the marking points downwards.

The hub must not rotate during this procedure.

– First hand-tighten the lowest wheel bolt to about 30 Nm.
– Then tighten the remaining wheel bolts diagonally to about 30 Nm. This process ensures that the wheel is centred properly on the hub.
– Check whether the imbalance is less than 20 grams using the finish balancer.

The imbalance should always be less than 20 grams before you change the balance weight.

– If necessary, remove the wheel bolts again.
– Rotate the wheel relative to the hub once more, turning it one or two wheel bolt holes further.
– Tighten the wheel bolts using the method described above.

Do not try to reduce the imbalance using balance weights until the imbalance is less than 20 grams.

Always tighten wheel bolts to specified torque using a torque wrench!

Radial and lateral runout occur when the wheel and tyre do not run absolutely true. For technical reasons, 100% true running is not possible. Therefore, the manufacturers of these components allow a precisely determined tolerance. Mounting the tyre in an unfavourable position on the wheel can cause the maximum allowed tolerance for wheel with tyre to be exceeded. The table shows the maximum permissible tolerances for a wheel with mounted tyre.

Tolerances for radial and lateral runout of wheels with tyres

Checking lateral runout

– Preload tyre gauge about 2 mm.
– Set tyre gauge against sidewall of tyre.
– Slowly rotate the wheel.
– Note the smallest and the largest dial readings.

If the difference is greater than 1.3 mm, the lateral runout is too great. In this case, you can reduce lateral runout by match mounting the tyre. Extreme values on the tyre gauge due to small irregularities in the rubber may be disregarded.

Checking radial runout

– Preload tyre gauge about 2 mm.
– Set the tyre gauge against the tyre tread.
– Slowly rotate the wheel.
– Note the smallest and the largest dial readings.

If the difference is greater than 1 mm, the radial runout is too great. In this case, you can reduce radial runout by match mounting the tyre. Extreme values on the tyre gauge due to small irregularities may be disregarded.

– Mount the wheel on the wheel balancer.
– Use the wheel balancing machine centring system -VAS 5271-.
– Preload tyre gauge about 2 mm.
– Slowly rotate the wheel.
– Note the smallest and the largest dial readings.

S – Lateral runout
H – Radial runout

– Compare the measured values with the specifications in the table.

Extreme values on the tyre gauge due to small irregularities may be disregarded.

Specifications for radial and lateral runout on wheel rim

If the measured value exceeds the specification, acceptably smooth running cannot be attained.

General

When radial or lateral runout of the wheel and tyre coincide, the imbalance of the wheel is amplified by the tyre. For technical reasons, 100% true running is not possible. Before match mounting the used wheels which are fitted on the vehicle, run the tyres warm. This will eliminate any flat spots caused by storage or handling.

Procedure for match mounting

– Deflate the tyre.
– Press the tyre beads off the rim flanges.
– Coat the tyre bead all round with tyre fitting paste.
– Rotate the tyre 180° relative to the wheel.
– Inflate the tyre to approx. 4 bar.
– Mount the wheel with tyre on the wheel balancer.
– Check true running, that is, radial and lateral runout.

• If the specified values for radial and lateral runout are not exceeded, the wheel can be balanced to 0 grams. Specified values appear on the PDF.

• If the radial and lateral runout is not within the specifications, the tyre must be rotated again.

– Deflate the tyre and press the tyre beads off the rim flanges.
– Rotate the tyre 90° relative to the wheel (1/4 of a turn).
– Inflate the tyre to 4 bar again and check true running.

• If the specified values for radial and lateral runout are not exceeded, the wheel can be balanced to 0 grams.

• If the radial and lateral runout is not within the specifications, the tyre must be rotated again.

– Press the tyre off the rim flanges again as described above.
– Rotate the tyre 180° relative to the wheel (1/2 a turn).

If the radial and/or lateral runout is still not within the specifications, check the radial and/or lateral runout of the wheel.

If the measured values for radial and lateral runout of the wheel are within the specifications, the tyre has an impermissibly high radial or lateral runout. In this case, the tyre must be renewed.

• After the tyres have been fitted, there will be fitting paste between the tyres and the rim flanges.

• Therefore, severe braking and acceleration manoeuvres must be avoided for the first 100 or 200 km driven. The tyres may otherwise rotate on the rims and your work will have been in vain.

What is a flat spot?

The term flat spot describes a type of wear where one patch or spot of the tyre has become flat.

Flat spots caused by storage or handling also cause vibration in the same way as incorrectly balanced wheels do. It is important that flat spots on the tread caused by storage or handling are identified as such.

Flat spots caused by storage or handling cannot be balanced and they can reoccur at any time due to various circumstances. Flat spots caused by storage or handling can be eliminated without complicated special tools. This does not apply to flat spots caused by hard braking.

Flat spots caused by hard braking cannot be repaired. Such tyres must be renewed.

Reasons for flat spots caused by storage or handling:

• The vehicle has been left standing in one place without being moved for several weeks.

• The tyre inflation pressure is too low.

• The vehicle was placed in a paint shop drying booth after being painted.

• The vehicle was parked with warm tyres in a cool garage or similar for a long period of time. In this case, a flat spot from standing may even occur overnight.

Eliminating flat spots caused by storage or handling

• Flat spots caused by storage or handling cannot be eliminated from the tyre using workshop equipment.

• Flat spots caused by storage or handling can be removed only by running the tyres warm.

• The method described below is not recommended in cold and wintry weather.

Requirements and conditions:

– Check and, if necessary, correct inflation pressures.
– Drive the car on a motorway where possible.
– Traffic and road conditions permitting, drive a 20 to 30 km stretch at a speed of 120 to 150 km/h.

Do not endanger yourself or other road users during this road test. Observe the highway code and speed limitations in force when performing the road test.

– Raise the vehicle immediately following the road test.
– Remove the wheels from the vehicle.
– Balance the wheels on a stationary wheel balancer.

General

Perform a road test to determine whether a vehicle is pulling to one side and if so, which side. When wheel alignment is checked, include the wheel alignment test results in tyre complaint report.

Manufacturer’s tolerances can lead to a slight amount of taper (asymmetry) in the tyre carcass. The rolling tyre then develops a lateral force which acts directly on the wheel suspension, leading to self-steering of the vehicle. Strategic rotation of the wheels can compensate for this self-steering behaviour.

Conicity

Conicity is caused by a slight offset of the tread and/or the belt (amounting to a few tenths of a millimetre) relative to the geo-metric centre of the tyre. Conicity is not visible and cannot be measured with equipment available in the workshop.

Parts of a tyre
1 – Bead
2 – Shoulder
3 – Tread
4 – Steel cord belt
A – Geometrical centre of tyre
B – Actual centre of belt. It can be offset to inside or outside.

Exaggerated for clarity.
1 – Offset of belt and tread
F1 – Unequal vertical wheel forces
F2 – Unequal vertical wheel forces
Fk – Conicity force

The offset produces differences in stiffness at the inner and outer shoulders of the tyre, resulting in differing vertical wheel forces. Consequently the belt or tread will not be pressed onto the road surface with the same force (F1, F2). A conical, or tapered, shape develops. The resulting force (conicity force Fk) can, depending on the speed, become so great that the vehicle then pulls to one side.

If the force Fk on one wheel of the axle is, for example, 50 Newton, and also 50 Newton on the other wheel, and both forces are exerted in the same direction, the forces are cumulated. Reversing a tyre on the rim can compensate for the lateral pull because the forces then act in opposite directions.

Because the direction in which the force of taper is exerted is not visible, only road tests and strategic rotation of wheels and tyres can establish which tyres cause the pulling.

The tyre consists of numerous components and materials which are vulcanised to form a single part at the end of a complicated manufacturing process. The result is differing production tolerances which make themselves noticeable through more or less strong lateral forces (conicity forces). These forces can also occur in new tyres.

Pulling to one side on front axle

Pulling to one side can be caused by the running gear. However, experience shows that in 90% of all complaints, the tyres cause pulling to one side.

Pulling to one side during normal driving

On a straight, level road surface, the vehicle wants to pull to one side at a constant speed or with moderate acceleration. Force can be felt at the steering wheel.

Pulling to one side during fast acceleration

Pulling to one side during fast acceleration is, in part, due to the basic design of vehicles with front wheel drive. Different friction levels at the left and right wheels or possible irregularities in the road surface (potholes) and consequently varying road adhesion have a substantial influence on the handling characteristics. This does not constitute a complaint which is covered by the warranty.

Remedies when vehicle pulls to one side

Test conditions before and during the road test:

– Check all suspension components on the front and rear axles for damage.
– Check tyre pressure and correct if necessary.
– Check the tyres for external damage. Punctures, cuts, bubbles on the sidewalls, flat spots from braking and/or damage to the tread.
– Ask the customer if the tyre had been damaged by a nail or similar object and was repaired by a tyre dealer. It may be necessary to renew such tyres.
– Check tyres for even wear and tread depth.
– Are all tyres of the same type, manufacture and tread pattern?
– If the tyres are non-directional, ensure that all DOT classifications on the tyre face outwards. The wheels and/or tyres on the vehicle may have already been changed around at an earlier date.
– Is the make of tyre approved by the factory as original equipment?
– Perform the road test on a road which is level, straight and ungrooved and does not drop off to one side.
– Perform the road test with the customer under the conditions specified above. Ask the customer to demonstrate the problem.

There must be no crosswind during the road test.

If the complaint is justified, VOLKSWAGEN recommends rotating the wheels and tyres as described below.

Before you begin, observe the following notes; otherwise your efforts may not have the desired effect.

• Mark the tyres before the first rotation, e.g. FR, FL, RR, RL.

• After rotating wheels or reversing the tyre on its rim, you must observe very carefully how the vehicle behaves during the road test. Note how and what was changed.

• Assess the intensity of or a possible change in the tendency to pull to one side.

• For this purpose, it is important that the road tests are always performed by the same person on the same road. It is best to drive the „test course“ in both directions.

• Replacing a tyre with a new tyre does not guarantee that pulling to one side will be eliminated. Therefore it is recommended as a first step to carry out the strategic rotation of the wheels as described below.

• If there are large differences in the tread depth of the tyres on the front and rear axles, the tyres with the deeper tread should always be mounted on the front axle.

Strategic rotation of wheels having non-directional tyres

Perform a road test to determine if the vehicle pulls to one side and if so, which side.

If the vehicle pulls to one side, interchange the front wheels.

Perform road test

Vehicle travels in a straight line – END

Vehicle pulls to other side: Vehicle pulls to the same side

Interchange the front and rear wheels.

Perform road test

Vehicle pulls to other side: No change

Reverse one front tyre on its rim (direction of rotation is reversed).

Check alignment of front and rear wheels and adjust if necessary. If the alignment is correct, contact Product Support.

Perform road test

Vehicle travels in a straight line – END

Vehicle does not travel in a straight line

Interchange front wheels.

Perform road test

Vehicle travels in a straight line – END

Vehicle does not travel in a straight line

Mount new tyres on front axle.

Perform road test

Vehicle travels in a straight line – END

Vehicle does not travel in a straight line; contact Product Support.

Strategic rotation of wheels having unidirectional tyres

Perform a road test to determine if the vehicle pulls to one side and if so, which side.

If the vehicle pulls to one side, interchange front and back wheels with tyres.

Perform road test

Vehicle travels in a straight line – END

Vehicle does not travel in a straight line

First renew one tyre on the front axle.

Perform road test

Vehicle travels in a straight line – END

Vehicle does not travel in a straight line

Renew other tyre on the front axle.

Perform road test

Vehicle travels in a straight line – END

Vehicle does not travel in a straight line

Check front and rear wheel alignment.

Perform road test

Vehicle travels in a straight line – END

Vehicle does not travel in a straight line; contact Product Support.

As tyre damage can have serious consequences, you and the driver should regularly check the tyres to identify any problems at an early stage. Damaged tyres cannot withstand driving conditions such as high speed, long distances, sporty driving, and so on.

Damage can be caused in a number of ways:

• Driving with insufficient tyre pressure

• Assembly error when tyres were fitted on rims

• Damage by embedding objects

• Ageing

• Improper storage

Whenever a safety risk cannot be ruled out, the tyre must be renewed.

Cross section of a radial belted tyre

1 – Tread block
2 – Tread groove
3 – Tread
4 – Nylon ply
5 – Belt layers

• Usually made of steel

6 – Bead core

• Consists of steel wires vulcanised into rubber.

• Ensures secure seating of the tyre on the rim.

7 – Bead filler
8 – Rim flange protection

• Protects the rim and tyre from abrasion from, for example, contact with the kerb

• Tyres with Maximum Flange Shield (or rim protector bar) are marked with the abbreviation MFS.

The nylon ply -4-, belt layers -5-, bead cores -6- and bead filler -7- form the carcass. The carcass is the „load-bearing structure“ of the tyre.

A swelling in the sidewall of the tyre indicates that the substructure of the carcass has been damaged. Typical causes for such damage include, for example, driving over kerbs at a sharp angle. Pinching the tyre in this way can damage the carcass. The substructure of the tyre is stretched so far that individual fibres in the carcass may be broken. The extent of the damage depends on the speed of impact, the angle of impact, the tyre pressure, the axle load and the type of obstacle.

Pinch marks on tyre sidewall -arrows

• Driving over kerbs should be avoided.

• If driving over a kerb is unavoidable, do so very slowly and as square-on as possible.

Interior view of a tyre with a punctured carcass

Due to a severe impact, the carcass was pinched on the wheel rim flange and is ruptured in the contact area.

Damage inside tyre due to impact injury (double rupture)

Double rupture -arrows- caused by pinching when a kerb was driven over. Often not detectable from outside.

Cuts

Cut caused by a sharp-edged obstacle -arrow

Damage caused by foreign bodies

Driving over hard, pointed objects like nails, screws and the like can pierce the tyre. This always leads to tyre damage.

Damage due to embedded foreign body

Often, the object -marking- is so securely embedded in the tyre that it will not free itself even at higher speeds. Consequently, it can act as a plug and seal the tyre relatively well. This results in a gradual loss of pressure, which the driver will not notice immediately, but which can lead to sudden and complete tyre failure.

No repair should be attempted on a steel-belted tyre of which the structure has been punctured by a foreign body.

If the customer complains of a loss of air from a tyre, it is essential that you check for embedded foreign bodies.

No repair should be attempted on a steel belted tyre of which the structure has been punctured by a foreign body. Corrosion can develop on the steel wires. This will always lead to the separation of the rubber from the steel belt. Generally, one cannot determine when the foreign body was embedded. The tyre structure may already have been damaged as a result of driving with insufficient tyre pressure. Damaged belt wires will sooner or later lead to separation of the rubber from the steel belt. As a result, the tyre can fail completely at some point long after the tyre was first damaged.

Tyre damage caused by foreign bodies is not covered by the warranty.

The tyre pressure must be checked regularly. VOLKSWAGEN recommends checking tyre pressure every two weeks. The correct tyre pressure is especially important during long trips or if a heavy load is to be carried. A sporty driving style also requires correct or even slightly increased tyre pressure.

Slow loss of tyre pressure

The slow loss of tyre pressure is especially problematic because even experienced drivers often do not notice it. Insufficient tyre pressure and the related increase in flexing (internal friction) cause the tyre material to heat up considerably and may lead to the separation of the various components and rubber compounds. In the end, the tyre is usually destroyed completely. The cause for the slow pressure loss cannot always be determined because the tyre is severely damaged and components of the tyre are missing.

Separation of carcass and rubber

Excessive heating due to driving with substantially insufficient tyre pressure led to overheating and subsequent separation of the carcass from the rubber material -arrows-. The tyre shown here was periodically driven with an inflation pressure which was insufficient for the load. Typical evidence for this is the circumferential scuffing along the bead caused by the wheel flange and also the discolouration. Small, furrowed creases are visible along the inside of the sidewall. When the tyre rolls, strong shear forces develop between the lay-ers of steel cord, especially at the ends of the belts.

Tyres with wide, circumferential furrows near the bead

Wide, circumferential furrows near the bead -arrows- indicate that the tyre was driven with insufficient pressure. Driving a VOLKSWAGEN BORA VARIANT 1999 with insufficient tyre pressure or ignoring or not recognising tyre damage can have serious consequences. The tyre can no longer withstand the forces which develop when the vehicle is driven. The defects mentioned above severely restrict the function of the tyre. The rubber compounds separate, which results in the partial separation of tyre components or even its complete destruction.

The graph shows the temperature development of a tyre at a speed of 180 km/h.

A – When specified tyre pressure is maintained, the temperature will remain stable.
B – Danger zone: When tyre pressure is 0.3 bar below specification, the temperature rises to above 120° C at higher speeds.
C – Critical temperature threshold: A tyre defect will develop.
T – Temperature in °C
t – Travel time in minutes

Bead core broken during tyre inflation.

Modern radial tyres for passenger cars are mounted only on safety rims. Safety rims have a hump -1- running along the bead seat.

1 – Hump (double hump H 2), extended double hump (EH2)
2 – Rim flange
3 – Inner bead seat (e.g. tapered bead seat)
4 – Rim
5 – Wheel
6 – Well
7 – Outer bead seat (e.g. tapered bead seat)

The hump prevents the tyre from being pressed out of the bead seat during travel with insufficient tyre pressure.

When the tyre is inflated, the bead of the tyre may not slip completely over the outer rim hump. In this case, there is a danger of the bead core becoming over-stretched if the tyre pressure is too high. The steel wires would then rupture partially or completely. A broken bead core cannot be detected from the outside.

Special requirements for tyres with run-flat properties

Wheel rims with a raised double hump (Extended Hump EH2) are prescribed for tyres with run-flat properties (reinforced side walls). The raised double hump prevents the deflated tyre from slipping off its seat on the wheel rim when the tyre is run deflated.

To avoid damage, always observe the notes/instructions when fitting/removing tyres with run-flat properties.

Tyres with damaged bead cores are not seated safely and securely on the rim. Such tyres are a safety risk! In addition, there is a risk of the partly broken bead core breaking apart during continued operation and the tyre could suddenly tear open. If the bead core breaks during inflation, the carcass will also be destroyed.

Bead damage due to faulty or incorrect tyre fitting with tyre-fitting machine

The following errors, which may occur when tyres are fitted, can lead to severe tyre damage:

• If the opposite tyre bead is not seated completely in the rim well when the upper bead is rolled in on the tyre fitting machine.

• If the fitting head is improperly adjusted.

• If the edge of the fitting roller rolls onto the bead.

• If the guide rollers are worn or have sharp edges.

Split tyre bead

In these cases, the bead, which is under great tension, can be cut into in the direction of rotation, split and/or be pinched off down to the core wire. It is often possible to identify the tracks of the guide roller as it was applied or ran off where the damage occurred.

Both tyre beads as well as the bead seats must always be coated with assembly paste.

If fitting damage remains undetected, there is a danger that the tyre will fail later during operation. THEREFORE!

• Never fit a tyre without using assembly paste.

• Do not allow the bead seating pressure to exceed 3 bar.

• Do not allow the tyre inflation pressure to exceed 4 bar.

• When the tyre has been fitted, reduce the tyre pressure to the specified value.

Tyres with run-flat properties have reinforced side walls when comparing them with normal tyres. This reduces the slippage of the side walls and prevents the tyre flanks sticking when the tyres are run deflated. This ensures the vehicle remains controllable and the vehicle has almost normal driving characteristics. This alleviates the necessity to fit the spare wheel in dangerous conditions e.g hard shoulder of a motorway or in bad weather conditions.

A deflated tyre can be driven further to the next workshop (approx. 50 km (approx. 30 miles)) at a suitable speed (max. 80 km/h (max. 50 mph)) and in suitable driving style for the conditions, see Owner’s wallet.

After checking the respective wheel, the responsibility lies with the driver to decide if it is safe to drive further with the deflated tyre.

-I- Tyres with normal air pressure
1 – Tyres with run-flat properties (reinforced side walls -red-)
2 – Normal tyres

-II- Deflated tyre

When a normal tyre -2- deflates, the side walls are pressed against the wheel rims. The side walls heat up extremely or stick and are therefore destroyed when the tyre is deflated. Tyres with run-flat properties -1- are supported on the reinforced side walls (-red-). A special tyre mixture and the reduced walkability of the reinforced side walls reduces the heat created when the tyre is run and the vehicle remains controllable.

Please note the special requirements when using tyres with run-flat properties.

Identification

Distinguishing features: tyres with run-flat properties can be identified by one of the following abbreviations DSST, Euforia, RFT, ROF, RSC, SSR or ZP. The abbreviation is located on the flank of the tyre following the tyre designation of the respective tyre manufacturer.

Body
1 – Beading with beading core
2 – Side wall
3 – Reinforced side wall
4 – Wheel rim with extended hump (EH2) on both sides – prerequisite when using tyres with run-flat properties

Retrofitting/requirements when using run-flat tyres

Retrofitting run-flat tyres to VOLKSWAGEN models may only be undertaken if the tyres are fitted as standard or they are available as an option. These tyres may only be used on vehicles with a tyre pressure monitoring system as a pressure lose in the tyres is not always visible. This system warns the driver when an inflation pressure is less than a certain inflation pressure.

Permitted are:

Direct measuring systems
Indirect measuring systems

Tyres with run-flat properties may only be fitted on disc-type wheels with raised double hump (Extended Hump – EH2).

The special fitting/removal instructions must be observed.

A mixed installation with standard tyres is not permitted, even on same axle. Only in exceptional circumstances may a standard tyre be fitted e.g. for a short period or a limited distance. The special run-flat characteristics are lost, the driver must always be informed.

Please observe the recommended tyre manufacture.

Repairs

Tyres with run-flat properties must be replaced after they have been run deflated. The special fitting/removal instructions must be observed.

General information

– As with standard tyre/wheel systems, the disc-type wheel must also be checked before fitting.
– The disc-type wheel must be checked (for true running, runout and other damage) after a tyre has been run deflated, as a pot-hole etc. could cause damage the disc-type wheel rim.
– Damaged disc-type wheels must be renewed.

1 – Wheel rim flange

• Stop for tyre side beading

2 – Hump (H2) on both shoulders of rim

• Prevents the tyre slipping off the shoulder of the rim while driving through tight bends

• Extended hump (EH2) – prerequisite when using tyres with run-flat properties

3 – Well

• Eases fitting/removal of tyre

A – Width of wheel rim

• Distance between tyre contact surfaces on both rim edges of wheel

• Dimensions in inches

B – Wheel rim diameter

• Distance between tyre contact surfaces on op-posite tyre shoulders

• Dimensions in inches

C – Wheel offset

• Vertical distance between centre of wheel and wheel inner contact surface

• Dimensions in mm

D – Pitch circle diameter

• Diameter of circle for wheel bolt holes

• Dimensions in mm

E – Centre hole

• Used to centralize

• Dimensions in mm

Data on wheel rims

There are several items of information on the wheel rims. The following example shows the information needed for unambiguous identification of the wheel rim:

Wheel size: 6 J x 15
6 – Rim width in inches
J – Shape of wheel rim flange
15 – Rim diameter in inches

Wheel offset in mm: 43

Data on hump of bead seat: EH2
Extended Hump

Raised round hump on both rim shoulders. These ensure that when run-flat tyres are used without air pressure, they will not slip from bead seat. Rims with EH2 are required only if tyres with run-flat capability are fitted!

Pitch circle diameter

Split rim alloy wheels consist of several parts. The major parts are the rim and the wheel centre. These parts are bolted together with special bolts using a special process. This ensures that the wheel functions properly, that it is sealed and safe and that it runs true. These requirements are not guaranteed with workshop materials and under workshop conditions.

You must not dismantle or repair composite wheels!

Special tools and workshop equipment required

• Cartridge gun -V.A.G 1628-

• Removal wedge -3409-

• Hot air blower -V.A.G 1416-

Materials

• 1K Window adhesive -DH 009 100 A2-

• Silicone remover -LSE 020 100 A3-

Installing trim element

These alloy wheels are fitted with exchangeable trim elements. Follow these instructions during installation.

• Ensure bonding surfaces in alloy wheel and trim element are free of dust and grease.

• Clean bonding surfaces with silicone remover -LSE 020 100 A3-.

– Apply 1K window adhesive -DH 009 100 A2- to bonding surfaces -arrows- using cartridge gun -V.A.G 1628-.

• Adhesive bead: length = approx. 25 mm and diameter = approx. 10 mm.

– Push trim element -2- forcefully into alloy wheel -1-.
– Secure trim element -2- on inner side of alloy wheel -3- with clamping washer.

Minimum curing period: 3 hours at a minimum room temperature of 15 °C.

Alloy wheel must be rebalanced.

The trim element cannot be removed without causing damage to the element.

– Remove clamping washers -2- on inner side of alloy wheel.
– Heat outer side of trim element -1- with hot air blower -V.A.G 1416-.

Do not overheat tyres and alloy wheels.

– Release trim element -1- on inner side of alloy wheel using wedge -3409-.
– Grasp under a corner on the outside and pull trim element -1- forcefully off alloy wheel.

Regular care is required to maintain the decorative appearance of alloy wheels over a long period of time. In particular road salt and dust from brake abrasion must be thor-oughly washed off every 2 weeks; otherwise the finish of the alloy wheel will suffer.

Cleaning agents

Suitable cleaning agents:

• Plain water or water with soft soap

• Water and essence of vinegar

• Alloy wheel cleansers without acids or strong solvents

Do not exceed the soaking time of the cleaning agent. The shorter the recommended soaking time, the harsher and more aggressive the cleaning agent.

Damage to finish

If the finish is damaged, for example by stones, the damage must be repaired as quickly as possible.

Removing adhesive residue from glued balance weights on alloy rims

• Strong solvents and acids attack the finish on alloy wheels and the surface of the wheel becomes matt and milky. Therefore, these substances should not be used.

• To remove adhesive residue on alloy wheels, use alloy cleansers or a petrol-based cleanser. Do not exceed the soaking time of the cleaning agent.

• After cleaning or removing adhesive residue from wheels, rinse them with water.

Repairing a damaged wheel using heat treatment such as welding or the addition or removal of material is absolutely forbidden. Damaged or deformed wheel rims or wheel rims with cracked or deformed wheel bolt holes may not be repaired. Restoration may only be undertaken using approved and genuine paint materials. The manufactures guarantee no longer applies once a wheel rim has been restored.

Wheel rims with cracks along the edges may not be repaired and must be replaced immediately. Remachining, heat treatment and welding of all types is not permitted. Material reforming is not permissible.

Before restoring, the radial runout and lateral runout must not exceed the manufactures tolerance of 0.8 mm. Only cast alloy wheel rims may be filled using a filler putty. These wheels have the material identification AlSi xx stamped in the inner side. Forged wheels may not be painted. The restoration is limited to the painted surfaces. Bright machined wheels, which only have a clear coating, may not be repaired. Only surface damage on the viewed side (design surface) of the wheel may be restored. Restoring a damaged surface depth of 1 mm must not be exceeded. Only up to 50 mm may be removed/ filler filled on the outer boss.

1 – Valve body
2 – Valve core
3 – Valve cap

1. Valve body

The rubber valve for tubeless tyres is designed to create an air-tight seal in the hole in the rim. The elastic material of the rubber body presses tightly into the hole in the rim. In the case of valves with a threaded metal base, a rubber seal is used to seal the rim. The lateral faces of the rim hole are sealing surfaces. They must therefore be free of rust and dirt and must not be damaged.

2. Valve core

The valve core has the most important job in the valve. It creates a seal and enables the regulation of the air pressure. The small flat seal on the valve core can function correctly only if it is free of foreign particles, dirt and moisture. The compressed air system must be free of water and oil!

3. Valve cap

A valve cap must always be screwed onto the valve. It prevents dirt from getting into the valve. Dirt which may be in the valve would reach the seal of the valve plate when the tyre is inflated and cause a leak.

The valve must be renewed every time a new tyre is fitted.

If the vehicle is driven without caps on the valves, there is the danger that dirt may get into the valve. This leads to a gradual loss of air, which in turn can lead to the destruction of the tyre.

• Separation of carcass and rubber

• Wide, circumferential furrows near the bead

• Stripped tread or stripped protector

The valve cap must be fitted tightly to ensure air-tight sealing.

Vehicles with front-wheel drive exhibit more tread wear on the front wheels due to the greater forces they have to transmit. In order for all 4 wheels on the vehicle to have the same service life, VOLKSWAGEN recommends rotating the front and rear wheels and tyres. Ensure that uni-directional tyres are not reversed. The longer the tyre runs at one position, the more it wears at certain points. Therefore it is recommended to rotate the wheels at short intervals, for example every 5,000 km. Diagonal rotation is possible only with non-directional tyres. This method of wheel rotation is especially advantageous in the case of saw-tooth wear. If saw-tooth wear has already progressed and the tread is worn to more than 50%, only slight improvements would be achieved and rotation is not recommended. The elasticity of the tread blocks declines and the saw-tooth wear does not progress.

Perform the checks and follow the instructions listed below. This is important to ensure that the wheel bolts and the wheels are properly secured.

– Check to ensure that contact surfaces -arrows- on brake disc are free of corrosion and dirt.
– Check to ensure that contact surface -arrow- on centring seat of brake disc are free of corrosion and dirt.

– Check whether the wheel bolts can be easily screwed in by hand. The thread of the wheel bolts must not come into contact with the bore in the brake disc -arrow-. If the thread of the wheel bolt touches the hole -arrow-, turn the brake disc relative to the wheel hub accordingly.

Remove dirt and corrosion, oil or grease from the contact surfaces, threads in the wheel hub and/or wheel bolts as necessary.

Damaged, badly corroded or difficult to remove wheel bolts must be renewed.

Fitting wheels

– Preserve wheel centring seat.
– When fitting the wheel, screw in all wheel bolts uniformly by hand.
– Tighten the wheel bolts in diagonal sequence to approx. 30 Nm.
– Lower vehicle to the floor and tighten all wheel bolts diagonally to the specified torque using the torque wrench.

Do not use an impact driver when screwing in the bolts!

Revised wheel bolts were used from model year 2001 and thereafter. These have the same dimensions and torque settings as the previous wheel bolts.

1 – For vehicles through model year 2000
Polished black surface – part no. -701 601 139 B-.
Not permitted on vehicles from model year 2001 or later.

2 – Wheel bolt for vehicles from model year 2001 and later
Collar -arrow- is not fixed in place on the hexagon.
Coated silver-coloured surface – part no. -7M3 601 139 B-.
Not permitted on vehicles to model year 2000.

The modified wheel bolts are not permitted on vehicles produced to model year 2000. Wheel rims from vehicles produced to model year 2000 are not permitted on vehicles from model year 2001 or later.

Notes on use of temporary spare wheels

Inform your customers about the following notes and, if appropriate, refer also to the user’s manual of the vehicle as the need arises.

The following notes also apply to spare wheels, e.g. 7 J x 16 with 205/55 R 16 tyres, marked with a yellow sticker with the text „MAX 80 km/h“ or „MAX 50 mph“.

• Depending on vehicle equipment, e.g. Passat cars with alloy wheels and 225 mm tyres have a spare wheel with the sticker described above instead of a temporary spare wheel.

• The spare wheel or temporary spare wheel is intended only for temporary use over short distances. Therefore, it must be replaces by a normal wheel as quickly as possible.

• After the temporary or spare wheel has been fitted, the tyre pressure must be checked as soon as possible. For the correct tyre pressure, please refer to the tyre pressure in the relevant vehicle or the relevant manual: Maintenance manual.

• Always observe the speed warning on the temporary spare wheel („MAX 80 km/h“ or „MAX 50 mph“).

• Full acceleration, hard braking and driving fast through curves should be avoided.

• Never drive with more than one spare wheel or temporary spare wheel.

• The use of snow chains on the temporary spare wheel is not permitted for technical reasons.

• If it is necessary to travel with snow chains, the temporary spare wheel must be fitted on the rear axle even if the front tyre has been damaged. The now available rear wheel must then be fitted in place of the defective front wheel.

Notes regarding the recommended makes of summer tyre

• Tyres are one of the most important elements in motor vehicle construction and have a major influence on road safety. Therefore, they must fulfil numerous conditions which are specified for tyre manufacturers in the DIN (German industrial standards) and the directives of the German rubber industry e. V. (W.d.K.). In addition, comprehensive testing is carried out at VOLKSWAGEN before tyres are approved for initial fitting on our vehicles.

• The following lists all tyre makes and tread patterns that are fitted to VW vehicles ex-factory, correct at the time of publication.

• These tyre makes/tread patterns meet the aforementioned demands. VOLKSWAGEN therefore recommends the tyres/tread types listed in this guide are chosen as replacements.

• Observe special requirements for tyres with run-flat properties.

Summer tyres Bora, Bora 4Motion model year 1999 to model year 2005

Notes regarding the recommended makes of all-season tyre

• Tyres are one of the most important elements in motor vehicle construction and have a major influence on road safety. Therefore, they must fulfil numerous conditions which are specified for tyre manufacturers in the DIN (German industrial standards) and the directives of the German rubber industry e. V. (W.d.K.). In addition, comprehensive testing is carried out at VOLKSWAGEN before tyres are approved for initial fitting on our vehicles.

• The following lists all tyre makes and tread patterns that are fitted to VW vehicles ex-factory, correct at the time of publication.

• These tyre makes/tread patterns meet the aforementioned demands. VOLKSWAGEN therefore recommends the tyres/tread types listed in this guide are chosen as replacements.

• Observe special requirements for tyres with run-flat properties.

All-season tyres Bora, Bora 4Motion model year 1999 to model year 2005

Notes regarding the recommended makes of winter tyre

• Tyres are one of the most important elements in motor vehicle construction and have a major influence on road safety. Therefore, they must fulfil numerous conditions which are specified for tyre manufacturers in the DIN (German industrial standards) and the directives of the German rubber industry e. V. (W.d.K.). In addition, comprehensive testing is carried out at VOLKSWAGEN before tyres are approved for initial fitting on our vehicles.

• The following lists all tyre makes and tread patterns that are fitted to VW vehicles ex-factory, correct at the time of publication.

• These tyre makes/tread patterns meet the aforementioned demands. VOLKSWAGEN therefore recommends the tyres/tread types listed in this guide are chosen as replacements.

• Observe special requirements for tyres with run-flat properties.

Winter tyres Bora, Bora 4Motion model year 1999 to model year 2005