Mercedes-Benz CL-Class 2009 - Manual (Page 445)

Tires and wheels
443
Aspect ratio
Aspect ratio
2 is the dimensional
relationship between tire section height and
section width and is expressed in percentage.
The aspect ratio is arrived at by dividing
section height by section width.
Tire code
Tire code
3 indicates the tire construction
type. The “R” stands for radial tire type. Letter
“D” means diagonal or bias ply construction;
letter “B” means belted-bias ply construction.
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 example: 245/40 ZR 18). For
additional information, see “Tire speed
rating” (
Y page 443).
Rim diameter
Rim diameter
4 is the diameter of the bead
seat, not the diameter of the rim edge. The
rim diameter is indicated in inches (in).
Tire load rating
G Warning!
The tire load rating must always be at least
half of the GAWR of your vehicle.
Otherwise, tire failure may be the result
which may cause an accident and/or
serious injury to you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
G Warning!
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver’s door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also
result in handling or steering problems, or
brake failure.
Tire load rating 5 is a numerical code
associated with the maximum load a tire can
support.
For example, a load rating of 91 corresponds
to a maximum load of 1356 lb (615 kg) the
tire is designed to support. See also
“Maximum tire load” (
Y page 446) where the
maximum load associated with the load index
is indicated in kilograms and lbs.
For additional information on tire load rating,
see “Load identification” (
Y page 445).
Tire speed rating
G Warning!
Even when permitted by law, never operate
a vehicle at speeds greater than the
maximum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire
failure, causing loss of vehicle control and
possibly resulting in an accident and/or
serious personal injury and possible death,
for you and for others.
Regardless of the tire speed rating, local
speed limits should be obeyed. Use prudent
driving speeds appropriate to prevailing
conditions.
Tire speed rating
6 indicates the approved
maximum speed for the tire.
Summer tires
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)
Operation
Z