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 adjacent 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.
Snow tires lose their traction capability when their tread depth falls below 5/32 in. (4 mm).
In the United States, state laws may govern the minimum tread depth permissible. Follow all such laws.
Driving on worn tires can result in loss of control of the vehicle and could cause serious personal injuries or death.
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 damage, puncture
High-pressure cleaning units can damage the tires.
In case of tire damage, where it is uncertain whether there is a break in the ply with all its consequences or tire damage caused by thermal or mechanical overloading due to loss of pressure or any other prior damage, we recommend that the tire be replaced for safety reasons.
If one faulty tire is replaced it should be noted that the difference in tread depth on one axle must not exceed 30%.
Handling inconsistencies may result.
Damaged Tire Check
Driving the vehicle with low tire pressure increases risk of a tire failure and resulting loss of control. Furthermore, low tire pressure increases rate of wear of the affected tires.