Page 562 of 590

ratio is calculated by dividing the tire width by
the tire height.
Tire code:
tire code0027specifies the tire type.
"R" represents radial tires; "D" represents
diagonal tires; "B" represents diagonal radial
tires.
Optionally, tires with a maximu mspeed of
over 149 mph (240 km/h) may have "ZR" in
the size description, depending on the
manufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter0026is the
diameter of the bead seat, not the diameter
of the rim flange. The rim diameter is
specified in inches (in).
Load-bearing index: load-bearing index0024
is a numerical code that specifies the
maximum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum
permissible load can be found on the
vehicle's Tire and Loading Information
placard on the B-pillar on the driver's side
(Y page 555).
Example:
Load-bearing index 91 indicates a maximum
load of 1,356 lb (615 kg) that the tires can
bear. For further information on the maximum
tire load in kilograms and lbs, see
(Y page 562).
For further information on the load bearing
index, see "Load index" (Y page 561).
Speed rating: speed rating0025specifies the
approved maximum speed of the tire.
i Tire data is vehicle-specific and may
deviate from the data in the example.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic
conditions. Summe
r 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)
V up to 149 mph (240 km/h)
W up to 168 mph (270 km/h)
Y up to 186 mph (300 km/h)
ZR...Y up to 186 mph (300 km/h)
ZR...(..Y) over 186 mph (300 km/h)
ZR over 149 mph (240 km/h)
R
Optionally, tires with a maximum speed of
over 149 mph (240 km/h) may have "ZR"
in the size description, depending on the
manufacturer (e.g. 245/40 ZR 18).
The service specification is made up of
load-bearing index 0024and speed rating
0025.
R If the size description of your tire includes
"ZR" and there are no service
specifications, ask the tire manufacturer in
order to find out the maximum speed.
If a service specification is available, the
maximum speed is limited according to the
speed rating in the servic especification.
Example: 245/40 ZR18 97 Y.In this
example, "97 Y" is the service specification.
The letter "Y" represents the speed rating.
The maximum speed of the tire is limited to
186 mph (300 km/h).
R The size descriptio nfor all tires with
maximum speeds of over 186 mph
(300 km/h) must include "ZR", andthe
service specification must be given in
parentheses. Example: 560
All about wheels and tiresWheels and tires
Page 566 of 590

Maximum loade
dvehicle weight
The maximum weight is the sum of:
R the curb weight of the vehicle
R the weight of the accessories
R the load limit
R the weight of the factory installed optional
equipment
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa
corresponds to 1 psi. Another unit for tire
pressure is bar. There are 10 0kilopascals
(kPa) to 1bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifie sthe load-bearing
capacity more precisely.
Curb weight
The weight of a vehicle with standard
equipment including the maximum capacity
of fuel, oil and coolant. It also includes the air-
conditioning system and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
Maximum load rating
The maximum tire load is the maximum
permissible weight in kilograms or lbs for
which a tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire.
Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing the maximum axle load of one axle
by two.
PSI (pounds per square inch)
As tandard uni tofmeasure for tire pressure. Aspect ratio
Relationship between tire height and tire
width in percent.
Tire pressure
This is pressure inside the tire applying an
outward force to each square inch of the tire's
surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tire pressure
The tires are cold:
R
if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has been driven for less than
1 mile (1.6 km).
Tread
The part of the tire that comes into contact
with the road.
Bead
The tire bead ensures that the tire sits
securely on the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the
bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kilograms (5 lbs).
These optional extras, such as high-
performance brakes, level control, a roof rack
or a high-performance battery, are not
included in the curb weight and the weight of
the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used
by a tire manufacturer to identify tires, for
example for a product recall, and thus identify 564
All about wheels and tiresWheels and tires
Page 587 of 590

Vehicle data
General notes
Please note tha tfor the specified vehicle
data:
R The heights specified may vary as a result
of:
- Tires
- Load
- Condition of the suspension
- Optional equipment Dimensions and weights
Model 0002 Opening height
All models (except
for AMG vehicles)
75.8 in (1925 mm)
Model 0002 Opening height
AMG vehicles
76.0 in - 76.6 in
(1931 mm -1945 mm) SL 550
Vehicle length
181.6 in (4612 mm)
Vehicle length
when opening/
closing the roof
188.9 in (4797 mm) SL 550
Vehicle width
including exterior
mirrors
82.6 in (2099 mm)
Vehicle height
51.8 in (1316 mm)
Vehicle height,
when opening/
closing the roof
66.8 in (1697 mm)
Wheelbase
101.8 in (2585 mm)
Turning radius
36.2 ft (11.04 m)
Maximum trunk
load
220 lb (100 kg)
SL 63 AMG and
SL 65 AMG V12
Vehicle length
182.4 in (4633 mm)
Vehicle length
when opening/
closing the roof
191.3 in (4858 mm)
Vehicle width
including exterior
mirrors
82.6 in (2099 mm)
Vehicle height
51.2 in - 51.5 in
(1300 mm -1308 mm) Vehicle height,
when opening/
closing the roof
66.5 in - 67.4 in
(1688 mm -1713 mm) Wheelbase
101.8 in (2585 mm)
Turning radius
36.3 ft (11.05 m)
Maximum trunk
load
220 lb (100 kg) Vehicle data
585Technical data Z