4440IN Information on tyres/mounting tyres

WM 4440IN Information on tyres/mounting tyres

Information

Tyres

Tyre damage - caused while driving

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 that you replace the tyre in question for safety reasons.

Tyre damage - caused while removing/mounting tyres

When mounting 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 specified tyre mounting pastes. The following can occur if an unsuitable mounting paste is used:
- Twisting of the tyre on the rim.
- Fracture of the bead core during mounting and if the seating pressure is too high.
- Damage to the tyre bead.
- Damage to the rim surface by aggressive substances.

Replacing tyres

Tyres should not be more than 6 years old!

Tyres must not be repaired and the use of inner tubes in tubeless tyres is not permitted.

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 %.

If new tyres are mounted or the tyres of one axle are 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 to the other axle can cause a noticeable change in the usual vehicle handling. This is especially the case if new tyres are mounted on the rear axle. This effect decreases with increasing tyre mileage.

The overview of summer and winter tyres is included in Technical Information (TI), Group 4. When replacing summer tyres, pay close attention to the tyre specification number for the same make of tyre. The specification characters (for example N0) distinguish the summer tyres specially authorised by Porsche from other models of the same tyre type and size.

Customers should be informed that the full performance of new or newly mounted tyres is achieved only after driving the vehicle for a distance of 100 to 200 km (60 to 120 miles). Extreme driving manoeuvres (acceleration, braking) should be avoided.

Navigation system

After a wheel change, the full locating accuracy is attained only after a journey of approx. 50 km/30 miles (if possible on the motorway and at a speed > 60 km/h or 40 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 (6 psi).

If the tyres are not mounted on wheels, store them in the vertical position. Tyres stored in vertical position should be turned every two weeks in order to prevent excessive flattening. If the tyres are stacked in horizontal position, they will become severely deformed and cannot be seated in the rim flange easily when 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 tyres that are in continual use. Hairline ageing cracks can occur on older tyres. If tyres are in use, the kneading action activates the plasticizer in the rubber and thereby prevents hardening and cracking.

Tyre identification (speed classes/tyre age)

Tyres should not be more than 6 years old!

The age of the tyre can be determined from the manufacturer's code, which is placed 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