Porsche 928 GTS 1994 Owner's Manual page 119

Rims, tires
Summer tires
Snow tires
Collapsible spare tire
Tire pressure, front and rear with cold tires
Snow chains
front 225/45 ZR 17 on rims 7,5 J χ 17 H2 or AH (65 mm*)
rear 255/40 ZR 17 on rims 9 J χ 17 H2 or AH (55 mm*)
225/45 R 17 90 Τ M+S on 7,5 J χ 17 H2 or AH (65 mm*) rims front and
8 J χ 17 H2 or AH (52 mm*) rear
The load rating and code letter for maximum permissible speed (e.g. 90T) are minimum require­
ments. When fitting new tires or changing tires, follow the instructions in the section
"Tires/Wheels".
165/70-16 92 Ρ on 5.5 J χ 16 H2 rim. Maximum speed 50 mph or 80 km/h.
for summer tires 2,5 bar (36 psi) front and rear
for snow tires 2,5 bar (36 psi) front, 3,0 bar (44 psi) rear
Collapsible tire: 2,5 bar (36 psi)
Snow chains cannot be mounted on standard size wheels. Mounting is only possible on rear
wheels with snow tire size 225/45 R 17 on rims 8 J χ 17. Maximum speed 30 mph or 50 km/h.
See also section "Tires/Wheels".
*Rim offset
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