Mounting, Balancing & New Wheel/Tire Information
Mounting InformationAlways use new rubber valves when replacing tires. Rubber valve Part No. 900 265 001 50.
Before mounting tires, check for directional markings (arrow) or inside/outside markings.
Always coat tire beads with rubber lubricant when mounting tire on rim. Do not use silicone.
Wipe off lubricant before inflating the tire to reduce the possibility of tire slippage on the rim. For the same reason the customer should be informed to avoid fast acceleration or hard braking during the first 150 miles after tire mounting.
Inflate tubeless tire after mounting, but without valve insert, to approx. 4 bar pressure to guarantee correct fit of tire on rim. Tire beads must jump over the hump of the rim shoulder no later than when reaching a pressure of 3.3 bar, in order to avoid rupturing the bead core.
Screw in valve insert and set the tire inflation pressure to specified value.
Forged 7", 8" and 9" Porsche rims must be fitted with specified valve supports to avoid excessive loads on the rubber valves.
Support Part Number:
911 361 561 01
Some 7" cast aluminum rims have a casting boss to support the valve stem and do not need a valve support.
On rims which have this cast boss, the wall thickness at the valve hole will be so large that when installing tubeless tire valves the 3 mm wide bead ring must not be pulled through - as is common for steel rims. Pulling the valve bead through would cause excessive expansion of the valve.
New Tire Instructions:
Always use tires of the same make and type.
When changing tires of only one axle set, new tires should be mounted on wheels of front axle (unless tires are different front and rear).
If replacing only one tire of an axle set, the difference in tread depth between tires must not exceed 30%.
Before removing a wheel, the wheel stud closest to the tire valve should be marked with paint to ensure correct reinstalling of the balanced wheel. The lockable wheel nut must be installed on this stud. Refer to Bulletin Group 4, Number 8701, for balancing information.
Matching tires with forged rims
A machined depression on the rim well (of the perforated disc wheel rim) marks the point of highest radial run-out.
A red locating dot is pasted on the outside of the rim to mark the same point of highest radial run-out.
Tires are marked with a paint dot.
Align dots when installing tire on rim.
Dots must be within 30 mm (1-3/16 in.) of each other.
If the red locating dot is missing, mark the location of machined depression with chalk or tape before installing tire.
Balancing Weights
Use only single balance weights of maximum 40 grams each on vehicles with brake pad wear indicators and 15" wheel rims. Sufficient clearance can not be guaranteed if larger weights are used.
Wheel Nuts
A. Part No. 999 182 003 36 aluminum, for all Porsche rims with five mounting holes (especially aluminum rims) tightening torque 130 N-m (96 ft.lbs.)
B. Part No. N 020 112 1 for all rims with five mounting holes (especially steel rims) tightening torque 130 N-m (96 ft.lbs.)
Aluminum Wheel Nuts
Aluminum wheel nuts require special care.
Before installing:
- lubricate threads and shoulders of aluminum nuts with Optimoly TA, Part No. 000 043 020 00. (Optimoly TA does not affect tightening torque.) Torque nuts to 130 N-m (96 ft.lbs.)
Note: Tighten and loosen aluminum nuts with a socket that grabs the entire depth of nut such as Porsche tool No. P300.
CAUTION Other socket wrenches or wheel wrenches are not approved. Never use impact tools.
Break-in time for new tires.
New tires have a vulcanization skin that can cause poor vehicle handling. Handling characteristics improve measurably during the tire break-in period of 300 miles (500 km). Vehicle handling characteristics should not be evaluated immediately after tire replacement.
Driving conservatively during the first 300 miles (500 km) will help to maximize tire life. After the break-in period, recheck wheel balance.
Conditions leading to slow air loss or structural damage
^ damage to bead during installation
^ installation damage from excessive expansion of bead core; tire could part from rim
^ installation damage to inside of tire; could cause loss of air or ply separation
^ punctures from foreign objects (nails, glass, rocks, etc.); moisture can cause rust at puncture
^ squeezing damage (from driving over potholes, curbs, or similar objects)
^ sidewall damage (from rubbing against curb or slipping off road shoulders)
^ cuts in tire (especially sidewalls)
^ damage from underinflation
CAUTION:
Porsche recommends replacing a tire if there is damage to the tread or sidewall and any possibility of structural deterioration.
Note: Repairing tires with pressurized sealants or tubes is not acceptable.
Retreading tires is not acceptable.
Damage that impairs true-running of wheels
^ Flat spots from standing under high temperature conditions. Tires may develop flat spots on the contact surface during long periods of standing. Driving the car should correct this condition.
^ Uneven wear from damaged suspension parts or misalignment. Checking/ correcting wheel alignment is necessary along with the replacing of damaged parts.
^ Uneven wear from improper balancing. Correct balancing must be performed before damage occurs.
^ Flat spots from locked wheels while braking. This damage usually remains noticeable and cannot be repaired.
When checking tire pressure, also check condition of tires. Look for uneven tire wear, damage to tires and rims and damage to suspension parts.
Porsche recommends checking wheel alignment following the first 1800-3000 miles (3000-5000km) of driving, or after any repairs to the suspension system.
Supporting Webs
Winter tire treads will usually have supporting webs in the tread base which could stop drainage when the treads are worn to a height of approximately 4 mm. It is then necessary to drive especially careful on wet roads.
The appearance of the support webs signals the need for tire replacement.