Flat Spotting - Saab 2003 9-5 2.3 Turbo Ecopower Owner's Manual

Tightening sequence, wheel bolts
WARNING
Grit, salt and rust can clog the inner
threads if the car has been driven for sev-
eral years exclusively with alloy wheels.
If steel wheels are now fitted, the bolt hole
threads in the brake hubs should be
cleaned before the thinner steel wheels
are fitted. It may otherwise not be possi-
ble to achieve the required clamping force
despite tightening the bolts to the correct
torque.
Removing the wheel cover
Car care and technical information

Flat spotting

All tires get hot, especially on long journeys
or when the car is driven hard. After the car
has been parked with hot tires and the tires
have cooled down, a flat spot can appear in
the tire, where it is in contact with the
ground. The same can occur if the car has
not been moved for a long time.
Flat spots can give rise to vibration that can
be felt through the steering wheel, similar to
that experienced when the wheels need bal-
ancing. Flat spots of this type disappear
once the tires get hot again, usually after
10–15 miles (20–25 km) of driving at cruis-
ing speed.
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