Wheels/Tires - Summer Tires/Wheels & Spacers
Boxster (987)1/06 ENU 4440
Summer Tires, Wheels and Spacers
Note
This technical information bulletin replaces TI Group 4, # 4/05, dated October 21, 2005.
Vehicle Type:
Boxster (987)/Boxster S (987)
Model Year:
As of 2005
Situation:
New wheels, spacers approved - status: March 2006.
Mixed tires.
^ Mixed tires result in uncontrollable vehicle handling.
--> Only tires of identical type and make and with the identical speed index and specification code (N0, N1, .2....) can be used on the same vehicle.
Makes/Types:
Note
N... = Specification code of the tire, e.g. "NO", "N1", "N2".., The complete "N..." code of the tires in question must be shown on the tire sidewall near the tire type designation.
Instructions for correct mounting of the tires are also given on the tire sidewall. If there are no mounting instructions on the tire sidewall, the tire must be mounted so that the DOT marking is visible from the outside.
Arrow with inscription "Rotation" = directional mounting.
"Inside/Outside" inscription = mounting on specified side only.
Arrow with both inscriptions "Rotation" and
"Inside/Outside" = directional mounting on specified side only.
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 cracks1 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 tire valve at every tire change.
Note
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, replace the tire in question for safety reasons.
Repairs to "V", "W", "Y" and "ZR" tires are not permissible, as well as the use of inner tubes in tubeless tires. Please inform your customers accordingly. It is advisable to mount winter tires at temperatures below 45° F17 °C, because the driving characteristics of summer tires are reduced at low temperatures. Extremely low temperatures can cause permanent damage to summer tires.
Tire Pressure:
Note
The tire pressure applies only to the tire makes and types approved by Porsche, and is specified for cold tires (approx. 68° F120 °C. The tire pressures must never be lower than the specified values.
Sizes:
Permissible summer tire and wheel sizes (RO = rim offset in mm)
Subsequent Installation Of Spacers
Securing spacers and wheels
The 5-mm thick spacers are secured on the wheel hubs together with the brake discs using countersunk screws (M6x16), Part No. 900.269.106.09.
Tightening torque 10 (7.5 ftlb.) Nm
The 5-mm spacer must remain on the vehicle when mounting the spare wheel.
The wheels must be secured using the 5-mm longer wheel bolts used on the 911 GT3, Part No.996.361.203.90. These wheel bolts are marked with GT or with a red color on the front of the bolt head (Arrow) or the rotating spherical cap is galvanized in red.
Length "x" approx. 50 mm
Tightening torque 130 (96 ftlb.) Nm
If the spacer is removed, the original wheel bolts, Length "X" approx. 45 mm, must be used again.
Wheels:
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.
Overview of Porsche wheels for summer tires Identification on the inside/outside of the wheel disc:
Wheel size, rim offset (RO) in mm, Part No. and Porsche logo
Wheel Mounting:
Tightening torque 130 (96 ftlb.) Nm
Navigation system:
After a wheel or tire change, the full locating accuracy is attained only after a trip of approx. 30 miles/50 kilometers (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 "440594 Balancing wheels"
--> Workshop Manual "4400IN Tyre failure/tyre sealant"
--> Workshop Manual "4400IN General tyre mounting instructions"
--> Workshop Manual "440007 Checking disc wheels"
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