Porsche Cayenne Owner's Manual page 285

Tire life
Tire life depends on various factors, i.e., road sur-
faces, traffic and weather conditions, driving
habits, type of tires and tire care.
f Inspect your tires for wear and damage before
driving off. If you notice uneven or substantial
wear, wheels might need alignment or tires
should be balanced or replaced.
Tire wear
The original equipment tires on your Porsche have
built-in tire wear indicators. They are molded into
the bottom of the tread grooves and will appear as
approximately 1/2 in. (12 mm) bands when the
tire tread depth is down to 1/16 of an in (1.6 mm).
When the indicators appear in two or more adja-
cent grooves, it is time to replace the tires. We
recommend, however, that you do not let the tires
wear down to this extent.
Worn tires cannot grip the road surface properly
and are even less effective on wet roads.
In the United States, state laws may govern the
minimum tread depth permissible. Follow all such
laws.
Danger!
Driving on worn tires can result in loss of con-
trol of the vehicle and could cause serious
personal injuries or death.
f Do not drive with worn tires or tires showing
cuts or bruises as they may lead to sudden
deflation and loss of control which could cause
severe personal injury.
f Specialized high performance tires on high
performance sport utility vehicles exhibit more
wear than those on a family sedan, or even a
high performance sedan.
Therefore, it is important to check your tire
pressure and condition at least every two
weeks.
f If you notice that tires are wearing unevenly,
consult your Porsche dealer.
Uneven wear may not always be due to improper
wheel alignment. It can be the result of individual
driving habits such as cornering at high speeds. If
the tire pressure is not checked and adjusted
regularly, abnormal tire wear can also occur.
Tire care
f Avoid damaging tires and wheel rims.
f If you must drive over a curb or other obstacle,
drive slowly and at an obtuse angle.
f Check tires for uneven wear and damage
before driving off.
f Remove imbedded material.
f Replace worn or damaged tires immediately.
f Keep oil, fuel, brake fluid, etc. away from tires.
f Replace missing valve stem caps.
f Keep tires inflated correctly.
f Wash tires when washing the vehicle. Also
clean inner side of wheels.
f Do not use abrasive cleaners when washing
the wheels.
f Check wheel rims for corrosion.
f Remove road salt, if driving in winter.
Minor Repairs
285