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

120 Vehicle care
Remove the valve cap key from the
fuel filler flap and use it to unscrew the
valve cap.
Tyre pressure 3 150 and on the label
on the inside of the fuel filler flap.
The tyre pressure data refers to cold
tyres. It applies to summer and winter
tyres.
Always inflate the spare tyre to the
pressure specified for full load.
The ECO tyre pressure serves to
achieve the smallest amount of fuel
consumption possible.
Incorrect tyre pressures will impair
safety, vehicle handling, comfort and
fuel economy and will increase tyre
wear.
9 Warning
If the pressure is too low, this can
result in considerable tyre warm-
up and internal damage, leading to
tread separation and even to tyre
blow-out at high speeds.

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).
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
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 reprogram the
speedometer 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.