Volkswagen Golf Service & Repair Manual: Tyre ageing
Even visually flawless, new or barely used tyres with
sufficient tread depth, which are older than six years, may show
significant reduction of wet properties and winter suitability
due only to ageing. |
Tyre tests show that a continuous development process, the
use of new rubber compounds and modern raw materials, in
conjunction with the optimisation of tread design and tread
geometry, make it possible to continually improve tyres. |
Only tyres with state-of-the-art technology can meet the
requirements of modern and highly developed vehicles and the
constantly growing demand from the customer for economical tyres
offering maximum possible safety, driving dynamics and comfort. |
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, among other things, the production date of the
tyre. |
Example of a DOT number to 31.12.1999 |
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DOT |
...... |
5 |
0 |
9 |
< |
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|
Stands for 199_ |
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|
Last digit is
production year |
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Week |
In this example, the production date is the 50th week of
1999. |
Example of a DOT number from 01.01.2000 |
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DOT |
...... |
0 |
1 |
0 |
0 |
|
|
|
|
|
Last 2 digits is
production year |
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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 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. |
Tyres must always be renewed when: |
the legal minimum tread depth of 1.6 mm is reached, |
there is visible mechanical damage |
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The energy loss caused by the deformation of the tyre when
rolling is known as rolling resistance.
With rolling resistance optimised tyres the deform ...
The tyre industry produces tyres with flange protection for
alloy wheels. The flange protection is intended to protect alloy
wheels from damage due to contact with ke ...
Other materials:
Special driving situations
Fig. 170 A: vehicle in a bend B: motorbike
in front is outside the range of the radar sensor
Fig. 171 C: vehicle is changing lanes.
D: turning vehicle, stationary vehicle
First read and observe the introductory information
and safety warnings The Adaptive Cruise Control (ACC) has physica ...
Dimensions
Fig. 21 Dimensions
First read and observe the introductory information
and safety warnings The data in the table apply to the most basic German
model.
The specified values can vary due to different tyre and wheel sizes, if additional
equipment is fitted, for different model versions, for ...
Absorbent glass mat battery
Maintenance-free battery with a contained electrolyte and no
colour indicator
Lead-acid battery where the electrolyte is contained within
a microscopic glass mat (AGM). The battery is sealed and fitted
with valves.
...
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