Tread Depth; Changing Tyre And Wheel Size - Opel ASTRA Owner's Manual

9. Proceed to the right side front
wheel, and repeat the procedure
in Step 8.
10. Proceed to the right side rear
wheel, and repeat the procedure
in Step 8.
11. Proceed to the left side rear
wheel, and repeat the procedure
in Step 8. The horn sounds twice
to indicate the sensor
identification code has been
matched to the left side rear tyre,
and the tyre pressure sensor
matching process is no longer
active.
12. Turn off the ignition.
13. Set all four tyres to the
recommended air pressure level
as indicated on the tyre pressure
label.
14. Ensure the tyre loading status is
set according to the selected
pressure 3 93.

Tread depth

Check tread depth at regular
intervals.
Tyres should be replaced for safety
reasons at a tread depth of 2-3 mm
(4 mm for winter tyres).
For safety reasons it is recommended
that the tread depth of the tyres on
one axle should not vary by more than
2 mm.
The legally permissible minimum
tread depth (1.6 mm) has been
reached when the tread has worn
down as far as one of the tread wear
indicators (TWI). Their position is
indicated by markings on the
sidewall.
Vehicle care
If there is more wear at the front than
the rear, swap round front wheels and
rear wheels periodically. Ensure that
the direction of rotation of the wheels
is the same as before.
Tyres age, even if they are not used.
We recommend tyre replacement
every 6 years.
Changing tyre and wheel
size
If tyres of a different size than those
fitted at the factory are used, it may be
necessary to reprogramme the
speedometer as well as the nominal
tyre pressure and make other vehicle
modifications.
After converting to a different tyre
size, have the label with tyre
pressures replaced.
9 Warning
Use of unsuitable tyres or wheels
may lead to accidents and will
invalidate the vehicle type
approval.
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