911 (992)
4400

ENU

Manufacturer's Certificate

22/25

Standard tire pressure for summer tires
Standard tire pressure for summer tires (UHP)
911 GT3, 911 GT3 Touring-Package

Tire size

Wheel size

Axle

Standard
pressure up
to Vmax

Performance
pressure up to
290 km/h (180
mph)

Full load
pressure up
to Vmax
Touring (for
I-No. 4 seats);

255/35 ZR
20

9.5J x 20

FA

2.1 bar
(30 psi)

1.9 bar
(28 psi)

2.3 bar
(33 psi)

315/30 ZR
21

12J x 21

RA

2.3 bar
(33 psi)

2.1 bar
(30 psi)

2.5 bar
(36 psi)

Standard tire pressure for winter tires
Standard tire pressure for winter tires
911 GT3, 911 GT3 Touring-Package

Tire size

Wheel size

Axle

Standard pressure
up to Vmax

245/35 R 20

9J x 20

FA

2.3 bar
(33 psi)

2.3 bar
(33 psi)

305/30 R 21

11.5J x 21

RA

2.5 bar
(36 psi)

2.5 bar
(36 psi)

Snow Chains:
WARNING
Incorrectly installed snow chains
•

Uncontrollable vehicle handling

Þ
⇒

Do not exceed top speed of 50 km/h (30 mph).

Þ
⇒

Read assembly instructions (see also TEQUIPMENT accessory finder on the Internet).

Þ
⇒

Observe country-specific regulations.

Aug 12, 2025
Page 6 of 8

Full load pressure
up to Vmax

AfterSales

Touring (for I-No.
4 seats);

911 (992)

Manufacturer's Certificate

22/25

ENU

4400

4

Porsche offers the following snow chains as accessories:
Tire size

Porsche Part No.

Type of snow chain

305/30 R 21

992.044.690.A

Link-type chain, quick fit

The snow chain tension must be readjusted after driving about 3 km (2 miles)!

Wheel Storage:

•
•

Tires must be stored in a cool, dry and dark room with adequate ventilation.
Tires must never come into contact with fuel, oil, grease or chemicals.

•
•

Do not store summer tires in storage areas with ambient temperatures of less than 5° F (-15° C).
Complete wheel & tire assemblies can be stacked for storage; we recommend that you increase the tire
pressure by approximately 6 psi (0.4 bar).
Optimum conditions for storage of the complete wheels are provided by the Original Porsche storage
trolley, Part No. 000.044.000.38.
If the tires are not mounted on wheels, it is best to store them in a vertical position.
We recommend that you turn tires stored in this position every two weeks in order to prevent flat spots.
Tires that are stacked in a horizontal position will become severely deformed and cannot be seated
properly in the rim flange when they are mounted.

•
•
•
•
General
Information:

•
•
•
•
•

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.
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.

AfterSales

Aug 12, 2025
Page 7 of 8

4

911 (992)
4400

ENU

Manufacturer's Certificate

22/25

New Tires (Replacements):
•
•
•
•

If new tires are to be mounted or the tires of one axle are to be replaced, tires of the same make, 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 on the same axle by more than 30 %.
Refer to WM 449503 for specific details of the vehicle you are working on.
•
•

>The 2mm specification will be given here.
> If there is none listed then the default is 30%.

Repairs to Tires:
•
•

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 to "V", "W", "Y" and "ZR" tires are not permissible, as is the use of inner tubes in tubeless tires.

Tire Aging:
•
•
•
•
•
•
•

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.

Important Notice: Technical Bulletins issued by Porsche Cars North America, Inc. are intended only for use by professional automotive technicians who have attended Porsche service training courses. They are
written to inform those technicians of conditions that may occur on some Porsche vehicles, or to provide information that could assist in the proper servicing of a vehicle. Porsche special tools may be necessary in
order to perform certain operations identified in these bulletins. Use of tools and procedures other than those Porsche recommends in these bulletins may be detrimental to the safe operation of your vehicle, and
may endanger the people working on it. Properly trained Porsche technicians have the equipment, tools, safety instructions, and know-how to do the job properly and safely. Part numbers listed in these bulletins
are for reference only. The work procedures updated electronically in the Porsche PIWIS diagnostic and testing device take precedence and, in the event of a discrepancy, the work procedures in the PIWIS Tester
are the ones that must be followed.

© 2025 Porsche Cars North America, Inc.

Aug 12, 2025
Page 8 of 8

AfterSales