No. 52-25 Service Bulletin/Repair Instructions

911 (991)
Manufacturer's Certificate
52/25
ENU
4400
4
Approved: Wheels and Tires (52/25)

Revision:
This bulletin replaces bulletin Group 4 49/24, dated May 8, 2025.
Model Year:
As of 2014 up to 2016
Vehicle Type:
911 GT3 (991) / 911 R (991) / 911 GT3 RS (991)
Approval Status: November 2025

WARNING

Driving with different tires (mixed tires)

•
Uncontrollable vehicle handling
Þ

⇒
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
Þ

⇒
Reduce speed.
Þ

⇒
Drive according to the road conditions.
Summer Tires:
The 911 GT3, 911 R and 911 GT3 RS vehicles are fitted 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 (95Y) XL

RA: 305/30 ZR 20 (103Y)

XL
Michelin Pilot Sport Cup 2 N1

(Inside/Outside)

UHP tires

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

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

Michelin Pilot Sport 4S N0

(Inside/Outside)
AfterSales
Jan 5, 2026

Page 1 of 9
4
911 (991)

4400
ENU
Manufacturer's Certificate
52/25
Model
Tire size
Tire make and type/

Label value (Link to EU database)

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

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

only for 911 GT3

Dunlop Sport Maxx Race 2 N2

(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
Michelin Pilot Sport Cup 2 N2

(Inside/Outside)

UHP tires

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

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

Dunlop Sport Maxx Race 2 N1

(Inside/Outside)

UHP tires

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

Goodyear Eagle F1 Super Sport RS N0

FA: https://eprel.ec.europa.eu/qr/1576159

RA: https://eprel.ec.europa.eu/qr/530039
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.
Jan 5, 2026

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

Winter Tires:
52/25
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: https://eprel.ec.europa.eu/qr/412844

RA: Data currently not available

Pirelli Winter 240 Sottozero Series II N1

(rotation)

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

RA: https://eprel.ec.europa.eu/qr/594293

FA: 245/35 R 20 91V M+S

RA: 295/30 R 20 101V XL

M+S

only for 911 GT3

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/411498

Michelin Pilot Alpin 4 N1

(rotation)

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

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

In principle, only tires that at least correspond to the maximum vehicle speed may be installed on the vehicle.

There may be national exemptions for winter tires marked for M+S and 3PMSF (3 peak mountain snow flake),

which also permit tires that do not correspond to the maximum vehicle speed.
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
AfterSales
Jan 5, 2026

Page 3 of 9
4
911 (991)

4400
ENU
Manufacturer's Certificate
52/25
Arrow with both inscriptions “Rotation” and

“Inside/Outside”
= Directional mounting on specified side only
Arrow with both inscriptions “Rotation” and “Left” or

“Right”
= Directional mounting on specified side only
Information

As a general rule, Porsche does not recommend having tires repaired. Local legislation must always be

observed.

It is advisable to install winter tires for temperatures below 7 °C (44 °F), because the driving characteristics

of summer tires and UHP tires are reduced at low temperatures. Subfreezing temperatures can cause

permanent damage to summer tires and UHP tires.

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 this value is exceeded, we recommend that you replace both tires.

WARNING

Incorrect tire pressure

•
Uncontrollable vehicle handling
Þ

⇒
Adjust the tire pressure according to specifications. Never allow the pressure to fall below the minimum pressure.
Þ

⇒
Check age of tires. Recommendation: Replace tires that are more than 6 years old.
Þ

⇒
Perform visual inspections.
Þ

⇒
Use only tires approved 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. 20 °C/ 68 °F). The tire pressure must not 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
Jan 5, 2026

Page 4 of 9
AfterSales
911 (991)
Manufacturer's Certificate
52/25
ENU
4400
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)
911 GT3, 911 R

20-inch wheels

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