Volkswagen ID.3: Wheels, tyres. axle align. Tyre wear

• Factors influencing the service life of tyres
• Saw-tooth wear
• Wear behaviour of high-speed tyres
• Measuring tread depth
• One-sided wear
• Outer shoulder wear
• Cupping wear
• Wear in middle of tyre

Factors influencing the service life of tyres

Factors influencing the service life of tyres

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

Running gear modifications:

If “suspension lowering kits” and/or alloy wheels that have not been approved by the vehicle manufacturer are used as accessories, the wheel positions can be altered so that the specified alignment is no longer maintained while driving.

Even if the axle geometry adjustment is correct with the vehicle stationary during wheel alignment, the changed vehicle height and wheel positions can cause the wheel suspension to move differently when driving.

Uneven wear is then unavoidable.

Saw-tooth wear

Saw-tooth wear

Saw-tooth wear is a stepped wear pattern on the individual tread blocks → Fig. 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 motion -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 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 is 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 to 1000 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, reverse both tyres 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.

Wear behaviour of high-speed tyres

Wear behaviour of high-speed tyres

These tyres are designed for very high speeds. When developing these tyres, good grip in wet conditions is the main objective. The tread compositions do not have the same wear resistance as T and H tyres for lower speeds.

The life expectancy of high-speed tyres is therefore considerably lower in comparable conditions of use.

Measuring tread depth

Measuring tread depth

Note

♦ 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.

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

One-sided wear

This is often caused by driving style, but can be the result of incorrect wheel alignment.

Increased one-sided wear

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 specified toe-in 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 cupping wear.

Toe-out or negative toe-in

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

Toe-in or positive toe

Distance between front of wheels -A- is less than distance between rear of 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 a kerb 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 the vehicle manufacturer 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 offroad. 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 depending on the driving style is unavoidable. This condition can be compensated for by rotating 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 differences between the tread depths of the tyres on each axle, which can have negative effects on road holding.

♦ Saw tooth formation is a normal wear pattern, particularly if the driving style is very careful → Chapter. This can lead to increased rolling noise, which generally becomes less as the tread depth decreases. In the event of light saw tooth formation or if saw tooth formation is just starting, exchanging the wheels between axles is normally sufficient. If saw tooth formation is very pronounced, the wheels have to be changed in accordance with → Chapter so their direction of rotation is reversed. This does not apply for tyres with a directional tread pattern.

♦ 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 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 )

Outer shoulder wear

Outer shoulder wear

Unsuitable use of self-levelling adjustments on pneumatic suspension system

The use of the offroad level is recommended only for driving offroad. 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 depending on the driving style is unavoidable. This condition can be compensated for by rotating 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 differences between the tread depths of the tyres on each axle, which can have negative effects on road holding.

♦ Saw tooth formation is a normal wear pattern, particularly if the driving style is very careful → Chapter. This can lead to increased rolling noise, which generally becomes less as the tread depth decreases. In the event of light saw tooth formation or if saw tooth formation is just starting, exchanging the wheels between axles is normally sufficient. If saw tooth formation is very pronounced, the wheels have to be changed in accordance with → Chapter so their direction of rotation is reversed. This does not apply for tyres with a directional tread pattern.

♦ 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 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 )

Cupping wear

Cupping wear

Cupping wear on a tyre

Cupping wear runs at an angle of approx. 45° to the direction of rotation.

It usually occurs at one point only, but can also occur at several points around the circumference of the tyre.

Cupping wear occurs almost exclusively on the tyres on the non-driven wheels, in particular at the rear left. Cupping wear 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 cupping wear is often found in the area where the tyre components are joined.

Wheels with toe-in also roll with a tyre slip angle when the vehicle is driven in a straight line. This leads to diagonal strain in the contact area between the tyres and 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 you detect cupping wear, you should fit the wheels on the driven axle, assuming the cupping wear is identified at an early stage. Deeper cupping wear cannot be repaired.

Adjustment error

If a customer complains of “cupping wear”, the toe adjustment must be examined. If the adjustment is correct, the cause of the cupping wear is very probably the tyre itself.

Tyres with cupping wear caused by incorrectly set axle geometry at the wheels are not covered by warranty.

Wear in middle of tyre

Wear in middle of tyre

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.

Note

For safety reasons, 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 interchanging the tyres on 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 loading associated with centrifugal forces within the tyre and the transmission of drive forces.

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