Mercedes-Benz S-Class 2008 Owners Manual User Manual
Page 570
569
Operation
Tires and wheels
Tire width
The tire width
1 (
page 568) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio
2 (
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
The tire code
3 (
page 568) indicates
the tire construction type. The “R” stands
for radial tire type. Letter “D” means diag-
onal 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” (
Rim diameter
The rim diameter
4 (
page 568) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating
5 (
page 568) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 573) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.
Warning!
G
The tire load rating must always be at least
half of the GAWR (
page 576) of your vehi-
cle. Otherwise, tire failure may be the result
which may cause an accident and/or seri-
ous personal injury to you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
Warning!
G
Do not overload the tires by exceeding the
specified load limit or total load limit as indi-
cated on the Tire and Loading Information
placard located on the driver’s door B-pillar
page 553). Overloading the tires can
overheat them, possibly causing a blowout.
Overloading the tires can also result in han-
dling or steering problems, or brake failure.