Mercedes-Benz SL-Class 2007 Owners Manual - Manual (Page 306)

305
Operation
Tires and wheels
Summer tires
ț At the tire manufacturer’s option, any
tire with a speed capability above
149 mph (240 km/h) can include a
“ZR” in the size designation (for exam-
ple: 245/40 ZR18). To determine the
maximum speed capability of the tire,
the service description for the tire must
be referred to. The service description
is comprised of the tire load rating 5
( ୴ page 302) and the tire speed
rating 6 ( ୴ page 302).
If your tire includes “ZR” in the size
designation and no service
description
5 and 6 ( ୴ page 302) is
given, the tire manufacturer must be
consulted for the maximum speed ca-
pability.
If a service description 5 and 6
( ୴ page 302) is given, the speed capa-
bility is limited by the speed symbol in
the service description.
Example: 245/40 ZR18 97Y.
In this example, “97Y” is the service
description. The letter “Y” designates
the speed rating and the speed capabil-
ity of the tire is limited to 186 mph
(300 km/h).
ț Any tire with a speed capability above
186 mph (300 km/h) must include a
“ZR” in the size designation AND the
service description must be placed in
parenthesis. Example: 275/40 ZR 18
(99Y). The “(Y)” speed rating in paren-
thesis designates the maximum speed
capability of the tire as being above
186 mph (300 km/h). Consult the tire
manufacturer for the actual maximum
permissible speed of the tire.
Index Speed rating
Q up to 100 mph (160 km/h)
R up to 106 mph (170 km/h)
S up to 112 mph (180 km/h)
T up to 118 mph (190 km/h)
H up to 130 mph (210 km/h)
V up to 149 mph (240 km/h)
W up to 168 mph (270 km/h)
Y up to 186 mph (300 km/h)
(Y) above 186 mph (300 km/h)
ZR above 149 mph (240 km/h)