Wheels and tyres 168Tread wear indicators
The tread wear indicators show the condition of the tyre
treads.The original tyres on your vehicle have 1.6 mm high “tread wear
indicators” ⇒fig. 122 running across the tread. Depending on the
make, there will be 6 to 8 of them spaced at equal distances around
the tyre. Markings on the tyre sidewall (for instance the letters “TWI”
or a triangle) indicate the positions of the tread wear indicators.
The minimum tread depth required by law in Germany is 1.6 mm
(measured in the tread grooves next to the tread wear indicators).
Different figures may apply in other countries.
WARNING
To avoid putting safety at risk, the tyres must be replaced at the
latest when the tread is worn down to the tread wear indicators.•
Especially in difficult driving conditions such as wet or icy
roads, it is important that the tyres have sufficient tread depth.
The tread depth should same on the tyres of both the front and the
rear axles.
•
The decrease in driving safety due to insufficient tread depth is
particularly evident in vehicle handling, when there is a risk of aquaplaning in deep puddles of water and when driving through
corners. Braking is also adversely affected.
•
The speed has to be adapted accordingly, otherwise there is a
risk of losing control over the vehicle.
Replacing wheels and tyres
It is important to use the correct wheels and tyres when
replacement is necessary.– All four wheels must be fitted with tyres of the same type
and preferably the same tread pattern.
– If possible, tyres should be replaced at least in pairs and
not individually (i.e. both front tyres or both rear tyres
together).
– Never use tyres whose actual size exceeds the dimen-
sions of the factory-approved makes of tyre.
– If you wish to fit the vehicle with non-standard rims or
tyres, it is advisable to consult an Audi R8 dealer before
purchasing them.The tyres and wheel rims are an essential part of the vehicle's
design. The tyres and rims approved by Audi are specially matched
to the characteristics of the vehicle and make a major contribution
to good roadholding and safe handling ⇒.
The sizes of the rims and tyres approved for your vehicle are listed
in the vehicle's documents (e.g. EC Certificate of Conformity or COC
document
2)). The vehicle documents vary depending on the
country of residence.
Fig. 122 Tyre tread:
Tr e a d w e a r i n d i c a t o r s
2)COC = Certificate of conformityWARNING (continued)
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Wheels and tyres169
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data Understanding the tyre designations makes it easier to choose the
correct tyres. For example, radial ply tyres have the following tyre
designations marked on the sidewall:
235 / 35 R 18 91 Y
This contains the following information:
The manufacturing date is also indicated on the tyre sidewall
(possibly only on the inner side of the wheel):
DOT ... 1010...
means, for example, that the tyre was produced in the 10th week of
2010.
Please note that with some types of tyres, the actual tyre size can
differ from the nominal size marked on the tyre (for instance 235/35
R 18 91 Y), and there may be significant differences in the contours
of the tyres, even though the tyres are marked with the same
nominal size designation. When replacing the tyres, it is therefore
important to make sure that the actual size of the new tyres does
not exceed the dimensions of the factory-approved makes of tyre.
Failure to observe this requirement can affect the clearance needed
for the tyres. This could result in contact between the tyres and
suspension components or bodywork. The brake lines could also be
damaged and the vehicle's safety could be severely impaired ⇒.
When using tyres with the maximum permitted nominal dimen-
sions, this can also void the vehicle's registration.If you use tyres that are approved by Audi you can be sure that the
actual tyre dimensions will be correct for your vehicle. If you decide
to fit a different type of tyre, you must obtain the appropriate manu-
facturer's certificate from the tyre retailer to confirm that the tyres
are suitable for your vehicle. Keep this certificate in a safe place.
Your local Audi R8 dealer will be able to advise you on which tyres
may be fitted to your vehicle.
On vehicles with four-wheel drive, all four tyres must always be
fitted with tyres of the same type, make and tread pattern, as other-
wise the driveline can be damaged by continuous variations in the
wheel speeds. For the same reason, only use a spare wheel with the
same tyre dimensions as the normal road wheels.
It is not permissible to use a wheel which is of a type different to
those already fitted on the vehicle (for instance when using winter
tyres) - even if you have a puncture.
It is best to have all servicing of wheels and tyres performed by a
qualified workshop. They have the necessary special tools and
replacement parts, trained personnel and facilities for disposing of
the old tyres.
WARNING
•
It is very important to ensure that the tyres you have chosen
have adequate clearance. When selecting replacement tyres, do
not rely entirely on the nominal tyre size marked on the tyre; with
some makes of tyre the effective tyre size can differ significantly
from the nominal dimensions, even though the tyres have the
same size designation. Inadequate tyre clearance can result in
damage to the tyres or the vehicle, causing a serious safety risk. It
may also invalidate the vehicle's type approval for use on public
roads.
•
Avoid running the car on tyres that are more than 6 years old.
If you have no alternative, you should drive slowly and with extra
care at all times.
235
Tyre width in mm
35
Height/width ratio in %
R
Tyre construction: Radial
18
Rim diameter in inches
91
Load rating code
Y
Speed rating code letter
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Wheels and tyres 170•
If wheel trims are fitted after the car is purchased, ensure that
there is an adequate flow of air for cooling the brakes.For the sake of the environment
Old tyres must be disposed of according to the laws in the country
concerned.
Note
•
Tyres with the “R0” mark are specially matched to your Audi. We
recommend that you use these tyres only. Your Audi R8 dealer or
specialist retailer will gladly provide you with further information.
•
Never mount used tyres if you are not sure of their previous
history.
•
For technical reasons it is not normally possible to use wheel
rims from other vehicles. In some cases this also applies to rims
from other vehicles of the same model.
Wheel bolts
The wheel bolts are designed to suit the rims on your car.The wheel bolts are matched to the rims. When installing different
wheels (for instance alloy wheels or wheels with winter tyres) it is
important to use the correct wheel bolts with the right length and
correctly shaped bolt heads. This is essential for the secure fit of the
wheels and for the proper function of the brake system.
Audi R8 dealers have full information on the technical requirements
when installing or changing tyres, rims or wheel trims.
The wheel bolts should be clean and turn easily.
A special adapter is required to turn the anti-theft wheel bolts*
⇒page 182.
Winter tyres
Winter tyres will significantly improve the car's handling
in winter road conditions.–Use only radial ply winter tyres.
– Winter tyres must be fitted on all four wheels.
– Only use winter tyres of the correct type approved for
your vehicle.
– Please note that the maximum permissible speed for
winter tyres may be lower than for summer tyres.
– Also note that winter tyres are no longer effective when
the tread is worn down.
– After fitting the wheels you must always check the tyre
pressures. The correct tyre pressures are listed on the
sticker on the driver's door pillar ⇒page 167.In winter road conditions winter tyres will considerably improve the
car's handling. Due to their type of construction (width, rubber
compound, tread pattern), summer tyres give less grip on ice and
snow. This applies particularly to vehicles equipped with wide
section tyres or high speed tyres (code letters H, V or Y on the side-
wall).
Only use winter tyres of the correct type approved for your vehicle.
The sizes of the winter tyres approved for your vehicle are listed in
the vehicle's documents (e.g. EC Certificate of Conformity or COC
document
3)). The vehicle documents vary depending on the
country of residence. Also refer to ⇒page 168.
Winter tyres are no longer fully effective when the tread is worn
down to a depth of 4 mm.
WARNING (continued)
3)COC = Certificate of conformity
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Wheels and tyres171
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data The performance of winter tyres is also severely impaired by ageing,
even if the tread is still much deeper than 4 mm.
Winter tyres are subject to the following maximum speed limits
according to speed rating code letter: ⇒
In Germany vehicles capable of exceeding these speeds must have
an appropriate sticker attached so it is visible to the driver. Suitable
stickers are available from Audi R8 dealers and specialist retailers.
Please note regulations to this effect in your country.
Using winter tyres with V-rating
Please note that the generally applicable 240 km/h speed rating for
winter tyres with the letter "V" is subject to technical restrictions;
the maximum permissible speed for your vehicle may be signifi-
cantly lower. The maximum speed limit for tyres with a V-rating
depends directly on the maximum axle weights for your car and on
the listed weight rating of the tyres being used.
It is best to contact an Audi R8 dealer to check the maximum speed
which is permissible for the V-rated tyres fitted on your car on the
basis of this information.
WARNING
Exceeding the maximum speed permitted for the winter tyres
fitted on your car can cause tyre failure, resulting in a loss of
control of the vehicle – risk of accident.
For the sake of the environment
Summer tyres should be fitted again as soon as possible; they give
better handling on roads which are free of snow and ice. Summer
tyres produce less rolling noise, do not wear down as quickly and,
most importantly, reduce fuel consumption.Snow chains
Snow chains will improve the vehicle's handling on snow-
covered roads.– Snow chains can be used on the rear wheels only.
– Keep your speed below 50 km/h.Snow chains will improve braking ability as well as traction in winter
conditions.
For technical reasons snow chains may only be used on tyres with
certain wheel rim/tyre combinations.
Only use snow chains with fine-pitch links. The links must not
protrude more than 13,5 mm from the tyres (including tensioner).
Speed rating code letter
⇒page 168
Maximum speed limit
Q
160 km/h
S
180 km/h
T
190 km/h
H
210 km/h
V
240 km/h
(please note relevant restrictions)
Rim size
Rim offset
Tyre size
8.5Jx18
42 mm
235/40
8.5Jx19
42 mm
235/35
10.5Jx18
55 mm
285/35
10.5Jx19
55 mm
295/30
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