No. 31-21 Service Bulletin/Repair Instructions

911 (991)
Manufacturer's Certificate
31/21
ENU
4400
4
Approved Wheels and Tires (31/21)
Revision:
This bulletin replaces bulletin Group 4 25/19, dated August 28, 2019.
Model Year:
As of 2014 up to 2016
Vehicle Type:
911 GT3 (991)/911 R (991)/911 GT3 RS (991)
Approval

status:
May 2021
WARNING

Driving with different tires (mixed tires)

•
Uncontrollable vehicle handling

Only use tires of the same make and type, with the same speed index and the same specification code

(N0, N1, N2, ...) on a vehicle.

WARNING
Driving with sports tires

•
Aquaplaning on wet or muddy roads

Reduce speed.

Drive according to the road conditions.
Summer Tires:
The 911 GT3, 911 R and 911 GT3 RS vehicles are installed as standard with sports tires that were

developed specifically for motor sports.

(FA = front axle, RA = rear axle)

Model
Tire size
Tire make and type/

label value (link to EU database)
911 GT3, 911 R
FA: 245/35 ZR 20 (91Y)

RA: 305/30 ZR 20 (103Y)

XL
Michelin Pilot Sport Cup 2 N1

(Inside/Outside)

FA/RA: Data currently not available

Dunlop Sport Maxx Race 2 N1

(Inside/Outside)

FA/RA: Data currently not available
AfterSales
Jun 17, 2021

Page 1 of 9
4
911 (991)

4400
ENU
Manufacturer's Certificate
31/21
Model
Tire size
Tire make and type/

label value (link to EU database)
911 GT3
FA: 245/35 ZR 20 (95Y)

XL

RA: 305/30 ZR 20 (103Y)

XL
Michelin Pilot Sport Cup 2 N1

(Inside/Outside)

FA: https://eprel.ec.europa.eu/qr/411697

RA: https://eprel.ec.europa.eu/qr/413161

Michelin Pilot Sport 4S N0

(Inside/Outside)

FA: https://eprel.ec.europa.eu/qr/411317

RA: https://eprel.ec.europa.eu/qr/408604

Dunlop Sport Maxx Race 2 N1

(Inside/Outside)

FA: https://eprel.ec.europa.eu/qr/529754

RA: https://eprel.ec.europa.eu/qr/529745
911 GT3 RS
FA: 265/35 ZR 20 (99Y)

XL

RA: 325/30 ZR 21 (108Y)

XL

Not for Japan
Michelin Pilot Sport Cup 2 N2

(Inside/Outside)

FA: https://eprel.ec.europa.eu/qr/411773

RA: https://eprel.ec.europa.eu/qr/408335

Dunlop XL Sport Maxx Race 2 N1

(Inside/Outside)

FA: https://eprel.ec.europa.eu/qr/529768

RA: https://eprel.ec.europa.eu/qr/529767

Michelin Pilot Sport Cup 2 R N0

(Inside/Outside)

FA: https://eprel.ec.europa.eu/qr/411795

RA: https://eprel.ec.europa.eu/qr/409802
Information

Sports tires (Ultra High Performance Tires) are permitted on public roads and satisfy all legal

requirements and road safety criteria.

These tires are also designed for use on racing circuits (driving safety training courses, sports driving

schools, Clubsport events) and offer distinct advantages with regard to dry adhesion and wear-and-tear

compared to normal road tires.

The main features are a reduced tread depth as well as a special thread design and substructure.
Jun 17, 2021

Page 2 of 9
AfterSales
911 (991)
Manufacturer's Certificate

Winter Tires:
31/21
ENU
4400
Model
Tire sizes
Tire make and type/

label value (link to EU database)
911 GT3, 911 R
FA: 245/35 R 20 91V M+S

RA: 295/30 R 20 97V

M+S
Michelin Pilot Alpin 4 N1

(Rotation)
4
FA/RA: Data currently not available

Pirelli Winter 240 Sottozero Serie II N1

(Inside/Outside)

FA/RA: Data currently not available
911 GT3
FA: 245/35 R 20 91V M+S

RA: 295/30 R 20

97V/101V XL M+S
Michelin Pilot Alpin 4 N1

(Rotation)

FA: https://eprel.ec.europa.eu/qr/412844

RA: https://eprel.ec.europa.eu/qr/411498

Pirelli Winter 240 Sottozero Series II N0

(Rotation)

FA: https://eprel.ec.europa.eu/qr/594297

RA: https://eprel.ec.europa.eu/qr/594293
911 GT3 RS
FA: 245/35 R 20 91V M+S

RA: 315/35 R 20 110V XL

M+S
Michelin Pilot Alpin 4 N1

(Rotation)

FA: https://eprel.ec.europa.eu/qr/412844

RA: https://eprel.ec.europa.eu/qr/409024
Information

N... = Specification code of the tire, e.g. "N0", "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 or “Left” or “Right”
= mounting on specified side only
Arrow with both inscriptions "Rotation" and

"Inside/Outside"
= directional mounting and mounting on specified

side only
Arrow with both inscriptions “Rotation” and “Left”

or “Right”
= directional mounting and mounting on specified

side only
AfterSales
Jun 17, 2021

Page 3 of 9
4
911 (991)

4400
ENU
Manufacturer's Certificate
31/21
Information

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 permissable, 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° F/7°C , because the driving characteristics of summer tires are reduced at low temperatures.

Extremely low temperatures can cause permanent damage to summer tires.

WARNING

Incorrect tire pressure

•
Uncontrollable vehicle handling

Adjust the tire pressure according to specifications. Never allow the pressure to fall below the minimum

pressure.

Check age of tires. Replace tires that are more than 6 years old.

Perform visual inspections.

Use only tires recommended by Porsche.
Tire Pressure:

Information

The tire pressure applies only to the tire makes and types approved by Porsche, and is specified for cold

tires (approx. 68° F/20°C ). The tire pressures must never be lower than the specified values.

Standard tire pressure for summer tires

Wheel size
FA
RA
2.0 bar

(29 psi)
2.3 bar

(33 psi)
2.0 bar

(29 psi)
2.3 bar

(33 psi)
911 GT3, 911 R

20-inch wheels

911 GT3 RS

FA: 20-inch wheels

RA: 21-inch wheels
Jun 17, 2021

Page 4 of 9
AfterSales
911 (991)
Manufacturer's Certificate
31/21
4400
ENU
4
Standard tire pressure for winter tires

Wheel size
FA
RA
2.2 bar

(32 psi)
2.4 bar

(35 psi)
2.3 bar

(33 psi)
2.5 bar

(36 psi)

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