Tread Depth - Opel ASTRA Owner's Manual

224 Vehicle care
8. Place the relearn tool against the
tyre sidewall, near the valve stem.
Then press the button to activate
the tyre pressure sensor. A horn
chirp confirms that the sensor
identification code has been
matched to this wheel position.
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 that the sensor
identification code has been
matched to the left side rear
wheel, 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sensor matching process is no
longer active.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
information label.
14. Ensure the tyre loading status is
set according to the selected
pressure 3 98.

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.
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
remains the same.
Tyres age, even if they are not used.
We recommend tyre replacement
every six years.