Tires
TyresGeneral notes on fitting
General
Note!
^ Always use new rubber valves when changing tyres!
^ The metal valve only has to be replaced in certain cases!
^ When fitting tyres, the direction of rotation and the inner and outer sides should be noted!
^ Only use TIP TOP Universal or Contifix tyre fitting paste!
Before fitting tyres, check wheels for damage (cracks, dents, etc.) and radial and lateral runout. Maximum permissible radial runout and lateral runout of the light alloy wheels = 0.7 mm. Maximum permissible radial runout and lateral runout of the wheel with tyre = 1.25 mm. Values less than 1.0 mm - better around 0.5 mm -are desirable.
When fitting tubeless tyres, check the sealing surface of the tyre and the disc wheel for cleanliness and any signs of damage. Bear in mind here that the bead base performs the sealing function on tubeless tyres. When mounting the tyre beads, use only the prescribed tyre mounting pastes. The following can occur if an unsuitable mounting paste is used:
^ The tyre may twist on the rim
^ The bead core may break during fitting if the seating pressure is too high
^ Tyre beads may be damaged
^ The rim surface may be damaged by aggressive substances
If Contifix is used, apply sparingly to the tyre beads (due to risk of the tyre twisting on the rim). If possible, the vehicle should not be driven for 24 hours after tyre fitting or matching.
Note!
^ Customers should be informed that the full performance of new or newly fitted tyres is achieved only after a distance of 100 to 200 km (60 to 120 miles) has been driven. Extreme driving maneuvers (acceleration, braking) should be avoided.
^ The absolute limit on how far the tyre can turn on the wheel must be regarded as 20 mm. In addition, an optimum balancing result will be worsened.
^ Mark the relative positions of the tyre and wheel for reference.
In order to optimise smoothness of rolling, it is expedient - and necessary in individual cases - to fit the tyre in a favourable position with respect to the wheel (matching).
Uncontrolled matching
If necessary, turn the tyre on the wheel by 90° or 180° in order to achieve an acceptable value with regard to rolling smoothness (true running, imbalance and distribution of balance weights).
Controlled matching
With a balancing machine with matching program. In most cases, this produces an even better result with regard to the rolling smoothness (true running, imbalance and distribution of the balance weights) than can be achieved with uncontrolled matching.
Fitting
Caution! Injuries may occur as a result of tyre seating pressure that is in some cases high (a maximum of 4.0 bar must not be exceeded) caused by possible tyre or wheel damage (in a culmination of several negative factors).
^ The tyre must therefore be inflated in the tyre cage.
Tyre cage
- After fitting the tubeless tyres, inflate them without the valve insert to a maximum of 4.0 bar of overpressure in order to ensure that they are seated properly on the wheel. At the latest when the pressure reaches 4.0 bar, the tyre beads must pop out of the deep bed and over the hump of the wheel shoulder in order to avoid fractures of the bead core. If necessary, interrupt the process and coat all necessary surfaces with lubricant (tyre mounting paste) again. Then repeat the process. Screw in the valve insert and set the prescribed tyre pressure.
If new tyres are to be fitted or the tyres of one axle are to be replaced, tyres of the same make and with the same specification code must always be used on each of the two axles. If tyres are replaced on one axle only, the different tread depth compared with the other axle can cause a noticeable change in the familiar handling. This applies in particular if new tyres are fitted on the rear axle. This effect decreases with increasing tyre mileage.
Note!
^ If a tyre is damaged and it cannot be determined with absolute certainty that there is no ply damage - with all of its consequences - or if the tyre was thermally or mechanically overloaded due to a loss of pressure or other prior damage, we recommend replacement of the tyre in question for safety reasons.
^ When replacing a tyre on an axle, make sure that the tread depth of the new tyre does not differ from that of the other tyre by more than 30 %.
^ Repairs on the tyres are not permissible, neither is the use of inner tubes in tubeless tyres!
^ When replacing summer tyres, pay close attention to the lyre specification number.
The overview of summer and winter tyres is included in the Technical Information (TI), Group 4 notice. When replacing summer tyres, pay close attention to the tyre specification number for the same tyre make. The specification number (for example NO) distinguishes the summer tyres specially approved by Porsche from other models of the same tyre type and size.
Balancing weights
Type of balancing weights: adhesive weights as used previously (no special version necessary).
Affix both weights on the inner side.
Note!
^ Observe programme selection and operating instructions of the balancing machine.
Navigation system
After a wheel change, the full locating accuracy is attained only after a journey of approximately 50 km (31 mls) (if possible on the motorway and at a speed > 60 km/h (37.5 mph)). Furthermore, high wheel slip (e.g.: wheel spin) can result in temporary incorrect positioning.
Wheel storage
^ Tyres must be stored in a cool, dry and dark room with adequate ventilation. They must never come into contact with fuel, oil, grease or chemicals. Complete wheels can be stacked for storage. It is advisable to increase the tyre pressure by 0.4 bar.
^ If the tyres are not fitted on wheels, store them in a vertical position. Tyres stored in a vertical position should be turned every two weeks in order to prevent excessive flattening. If the tyres are stacked in a horizontal position, they will become severely deformed and cannot be seated in the rim flange easily when they are mounted.
Tyres age due to physical and chemical processes, which can impair their function. If they are stored for an extended period, they will harden and become brittle faster than do tyres that are in continual use. Hairline ageing cracks can occur on older tyres. If tyres are in use, the kneading action activates the plasticiser in the rubber and thereby prevents hardening and cracking.
Tyre age
Note!
^ Tyres should not be older than 6 years! Not even the spare wheel.
The age of the tyre can be determined from the manufacturer's code, which is listed behind the DOT code on the tyre sidewall! The date of manufacture (the last four digits) is located at the end of the code.
Example