Mercedes-Benz SL 2008 Owner's Manual page 187

Operation
Tyres and wheels
It is therefore recommended to additionally
equip your vehicle with the TIREFIT kit*
when fitting tyres that do not feature run-
flat properties, e.g. winter tyres.
i
A TIREFIT kit* is available from any quali-
fied specialist workshop, e.g. a Mercedes-
Benz Service Centre.
You will find notes on driving with a flat tyre
in the "Practical advice" section
( page 275).
Y
Tyre tread
G Risk of accident
Bear in mind that:
tyre grip decreases rapidly on wet roads
R
when the tread depth is less than 3 mm.
You should thus replace tyres that have
insufficient tread.
winter tyres should be replaced when the
R
tread depth is 4 mm or less because oth-
erwise they no longer provide adequate
grip.
the tread on a tyre may not wear evenly.
R
You should thus regularly check the tread
depth and the condition of the tread
184
across the entire width of all tyres. If nec-
essary, turn the steering wheel so that
you can see the tyre tread more easily.
You could otherwise lose control of the
vehicle and cause an accident due to the
reduced grip of the tyres on the road.
Tyre pressures
i
You will find a table of tyre pressures for
various operating conditions on the inside
of your vehicle's fuel filler flap
( page 175).
Y
The valid value for the spare wheel* is sta-
ted on the spare wheel and in the technical
data section.
G Risk of accident
Tyre pressure that is either too high or too
low has a negative effect on the vehicle's
driving safety, which could lead you to
cause an accident. You should therefore
regularly check the pressure of all your
tyres (including the spare tyre*), particu-
larly prior to long trips, and correct the
pressure as necessary.
To test tyre pressure, use a suitable pressure
gauge. The outer appearance of a tyre does
not permit any reliable conclusion about the
tyre pressure. On vehicles fitted with the elec-
tronic tyre pressure monitor*, the tyre pres-
sure can be checked in the on-board com-
puter.
G Risk of accident
Should the tyre pressure drop repeatedly:
Check the tyre for foreign bodies.
R
Check whether the wheel is losing air or
R
the valve is leaking.
Tyre pressure that is too low has a negative
effect on the vehicle's active safety, which
could lead to your causing an accident.
Tyre pressure changes by approximately
0.1 bar for every 10 °C change in ambient
temperature.
If you measure the tyre pressure in enclosed
spaces where the temperature differs from
the outside temperature, you will have to cor-
rect the measured value accordingly.
When the vehicle is driven, the tyre tempera-
ture, and with it the tyre pressure, will
increase depending on the road speed and
the load on the tyres.
Therefore, you should only correct tyre pres-
sures when the tyres are cold.
* optional