Porsche Cayman Owner's Manual page 233

– third four-digit code means tire type code.
– fourth four-digit code means date of
manufacture.
If, for example, the last four numbers read
0211, the tire was produced in the 2nd week
of 2011.
C – Tire ply composition and material
The number of layers in the tread and sidewalls
and their material composition.
D – Maximum permissible inflation pressure
The maximum permissible cold inflation pressure
to which a tire can be inflated.
f
Do not exceed the permissible inflation
pressure.
E – Maximum Load rating
The maximum load in kilograms and pounds can
be carried by the tire. If you replace tires always
use a tire that has the same maximum load rating
as the factory installed tire.
F – Radial
The identification indicates if the tire has radial
structure.
G – Term of tubeless or tube tire
Identification for tubeless tires.
Speed code letters
The speed code letter Y indicates the maximum
permitted speed for the tire.
This code letter is shown on the tire sidewall.
T up to 118 mph (190 km/h)
H up to 131 mph (210 km/h)
V up to 150 mph (240 km/h)
W up to 165 mph (270 km/h)
Y up to 185 mph (300 km/h)
(Y) up to 185 mph (300 km/h) as for Y tires.
Speeds of more than 185 mph
(300 km/h) are also possible at a
maximum tire load capacity of 85 %
(confirmation from tire manufacturer
required for speeds of more than
185 mph (300 km/h)).
Information
Tires with a maximum speed rating that is lower
than the specified maximum vehicle speed may be
mounted only if they bear an M+S identification on
the tire sidewall.
f
Please note that in addition to snow tires,
all-season tires are also subject to speed limits
and bear this identification.
f
Never drive faster than the speed rating of the
tires, and obey all speed and traffic laws.
G - Rim width in inches
H - Rim-flange contour code letter
I - Symbol for drop-center rim
J - Rim diameter in inches
K - Double hump
L - Rim offset in mm
Inscription on alloy wheels
The information is provided on the rear of the
spokes. The rim width in inches A and the rim
offset F are visible from the outside. This
information can be found near the tire valve.
Minor Repairs
231