Operation – Mercedes-Benz SL-Class 2009 Owners Manual User Manual
Page 226
Tires and wheels
224
Tire size designation, load and speed
rating
1
Tire width
2
Aspect ratio in %
3
Radial tire code
4
Rim diameter
5
Tire load rating
6
Tire speed rating
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above illus-
tration.
General: Depending on the design standards
used, the tire size molded into the sidewall
may have no letter or a letter preceding the
tire size designation.
No letter preceding the size designation (as
illustrated above): Passenger car tire based
on European design standards.
Letter “P” preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter “LT” preceding the size designation:
Light Truck tire based on U.S. design stand-
ards.
Letter “T” preceding the size designation:
Temporary spare tires which are high pres-
sure compact spares designed for temporary
emergency use only.
Tire width
Tire width
1
indicates the nominal tire width
in millimeters.
Aspect ratio
Aspect ratio
2
is the dimensional relation-
ship 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 rat-
ing” (
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
The tire load rating must always be at least
half of the GAWR of your vehicle. Other-
wise, 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.
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
Operation