Wheels/Tires - Winter Tires/Wheels and Snow Chains

911 (997)

8/05 ENU 4440

Date: Dec 13, 2005

Overview Of Winter Tires, Wheels And Snow Chains

Note
This Technical Information replaces Technical Information No. 3/04 September 15, 2004

Models:
911 Carrera (997)/911 Carrera S (997)

Model Year:
As of 2005

Situation:
Approved winter tire makes and types - status 08/2004





WARNING
Mixed tires.








Makes/Types:

Tire pressure is too low and/or from insufficient maintenance.

^ Increased risk of accidents

--> The tire pressure must never fall below the tire pressure indicated below.

--> Check tires at regular intervals for uniform profile wear and possible damage such as cracks, bulges, detachments in the running surface, penetration from foreign objects, etc.

--> Tires older than 6 years are to be replaced.

--> Never use solvents or other chemical substances on tires (e.g. for cleaning or dying).

--> Replace valve at every tire change.

If a tire is damaged and it is not possible to determine with absolute certainty that there is no ply damage - with all of its consequences - or if the tire was thermally and/or mechanically overloaded due to a loss of pressure or other prior damage, we recommend that you replace the tire in question for safety reasons. Repairs to "V" and "ZR" tires should also be avoided, as well as the use of inner tubes in tubeless tires. Please inform your customers accordingly.





Tire Pressure:





Sizes:
Permissible winter tire and wheel sizes (RO = rim offset)

ATTENTION
Damage to wheel surface.

^ Risk of surface damage if the tires/valves are not mounted according to equipment operating instructions, and/or if the wheel surface is not cleaned/cared for correctly.

--> Carry out tire removal and mounting with a bead holding-down device only.

--> Use a leather pad on the rim flange to support the valve insertion tool.

--> Use only the Porsche centering clamping set for balancing.

--> Do not clean the wheels with brushes (car wash or washing car by hand). Deep scratches in the surface coating of the wheel cannot be repaired by polishing.











Wheels:

Wheel Mounting:
Tightening torque 130 (96 ftlb.) Nm

Snow Chains

DANGER
Incorrectly fitted snow chains.

^ Uncontrollable vehicle handling and increased risk of accidents.

--> Observe fitting instructions from the chain manufacturer!

--> Do not exceed the maximum speed of 30 mph/50 km/h.

Sufficient snow-chain clearance is only possible by first removing any spacers that are installed.





Porsche offers the snow chains as accessories shown.

Navigation System:
After a wheel or tire change, the full locating accuracy is attained only after a journey of approx. 30 miles (50 km) if possible on a highway and at a speed > 38 mph (60 km/h). Additionally, high wheel slip factor (e.g. wheel spin) can result in temporary incorrect positioning.

General:
Always use new valves when changing tires.
Always observe any possible instructions concerning the rolling direction and/or specifying which side the tires must be mounted on. Refer to notes (if applicable).

Coat the tire beads and humps with mounting lubricant before mounting the tire. This ensures that the tire beads will slide over the humps easily. In order to prevent the tire from turning on the wheel, avoid extreme driving maneuvers (acceleration and braking) during the first (100 to 200 miles) with new or recently mounted tires.

In order to optimize smoothness of rolling, it is appropriate - and necessary in individual cases to mount the tire in a certain (favorable) position with respect to the wheel (matching). Matching (uncontrolled and controlled) is explained below:

Uncontrolled matching: Turning the tire on the wheel by 90° or 120° if necessary in order to achieve an acceptable value with regard to rolling smoothness (true running, imbalance and weight 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 weight distribution of the balance weights) than can be achieved with uncontrolled matching. Maximum permissible radial runout and lateral runout of the wheels < 0.7 mm. Maximum permissible radial runout and lateral runout of the wheels with tires < 1.25 mm. Values < 1.50 mm - ideally approx. 0.5 mm - are desirable.

The mounting pressure (seating pressure) of 58 psi/4.0 bar overpressure must not be exceeded before both tire beads are evenly seated on the rim flange.

If new tires are to be mounted or the tires of one axle are to be replaced, tires of the same make, the same type and with the same specification code must always be used on each of the two axles. If tires are replaced on one axle only, the different tread depth from that on the other axle can cause a noticeable change in the familiar handling. This is especially the case if new tires are mounted on the rear axle. This effect decreases with increasing tire mileage.

When replacing a tire on an axle, make sure that the tread depth of the new tire does not differ from that of the other tire by more than 30 %.

If a tire is damaged and it cannot be determined with absolute certainty that there is no ply damage - with all of its consequences - or if the tire was thermally or mechanically overloaded due to a loss of pressure or other prior damage, we recommend replacement of the tire in question for safety reasons.

Repairs on "ZR" tires are not allowed, as is the use of inner tubes in tubeless tires. Tires age due to chemical and physical processes, which can impair their function. Tires that are stored unused for an extended period harden and become brittle faster than tires that are in continual use. Hairline aging cracks can occur on older tires. On tires in continual use, the kneading action activates the plasticizer in the rubber and thereby prevents hardening and cracking.

Therefore, attention should be paid not only to the tread depth but also to the age of the tire. Tires should not be older than 6 years. The age of the tire can be determined via the DOT code on the sidewall, which indicates the production date of the tire: e.g. DOT 2201 22nd week of 2001

Tires/complete wheels 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 tire pressure by 0.4 bar. Optimum conditions for proper storage of the complete wheels are provided by the Original Porsche storage stand (trolley), Part Number 000 044 000 38.

If the tires are not mounted on wheels, it is best to store them in vertical position. Tires stored in vertical position should be turned every two weeks in order to prevent excessive flattening. If the tires are stacked in horizontal position, they will become severely deformed and cannot be seated in the rim flange easily when they are mounted.

If the tires are not mounted on wheels, it is best to store them in a vertical position. In this case the tires should be turned every two weeks in order to prevent excessive flattening. If the tires are stacked in horizontal position, they will become severely deformed and cannot be seated in the rim flange easily when they are installed.

References:
--> Workshop Manual "441000 Wheels and tyres/tyre pressure"
--> Workshop Manual "440519 Removing and installing wheel"
--> Workshop Manual "440593 Balancing wheels"
--> Workshop Manual "44 1201 Checking disc wheels"
--> Workshop Manual "441255 Replacing disc wheels"
--> Owner's Manual "6002 Wheels and tyres"
--> Owner's Manual "6003 Wheel bolts"
--> Owner's Manual "6005 Wheel change"





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