2009-2012 Boxster – Manual

2009-2012 Boxster – Manual

Page: 199

E Tire size for the rear axle
Check with your authorized Porsche dealer about the current release status.

F Recommended tire pressure for the rear axle.
These values are for cold tires (68 °F/20 °C).

G In vehicles with collapsible spare wheel:
Size and tire pressure of the spare wheel.

Tire traction


When driving on wet or slushy roads, a wedge of water may build up between the tires and the road. This phenomenon is known as "hydroplane" and may cause partial or complete loss of traction, vehicle control or stopping ability.

  • Reduce speed on wet surface to prevent this.

Tire life
Tire life depends on various factors, i. e., road surfaces, traffic and weather conditions, driving habits, type of tires and tire care.

  • 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 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.

Excessively-worn Tires

Driving on worn tires can result in loss of control of the vehicle and could cause serious personal injuries or death.

  • 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.
  • Specialized high performance tires on high performance sports cars 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.

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

  • Avoid damaging tires and wheel rims.
  • If you must drive over a curb or other obstacle, drive slowly and at an obtuse angle.
  • Check tires for uneven wear and damage before driving off.
  • Remove imbedded material.
  • Replace worn or damaged tires immediately.
  • Keep oil, fuel, brake fluid, etc. away from tires.
  • Replace missing valve stem caps.
  • Keep tires inflated correctly.
  • Wash tires when washing the vehicle. Also clean inner side of wheels.
  • Do not use abrasive cleaners when washing the wheels.
  • Check wheel rims for corrosion.
  • Remove road salt, if driving in winter.

Tire damage, puncture
High-pressure cleaning units can damage the tires.

  • Please see the chapter "HIGH-PRESSURE CLEANING UNITS, STEAM CLEANERS" on page 185.
  • Check tires for imbedded material, cuts, punctures, cracks and bulges (side wall) before driving off.

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.

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