Mercedes-Benz C-Class Convertible 2021 Operator's Manual page 372

370 Wheels and tires
First letter(s) 1 1 :
Without: passenger vehicle tires according to
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European manufacturing standards.
"P": passenger vehicle tires according to US
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manufacturing standards.
"LT": light truck tires according to US manu‐
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facturing standards.
"T": compact emergency spare wheels with
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high tire pressure that are only designed for
temporary use in an emergency.
Aspect ratio 3 3 :
Ratio between tire height and tire width in per‐
cent (tire height divided by tire width).
Tire code 4 4 (tire type):
"R" radial tire
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"D": bias ply tire
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"B": bias belted tires
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"ZR": radial tire with a maximum speed above
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149 mph (240 km/h) (optional)
Rim diameter 5 5 :
The diameter of the bead seat (not the diameter
of the rim flange). The rim diameter is specified
in inches (in).
Load-bearing index 6 6 :
Numerical code that specifies the maximum
load-bearing capacity of a tire (e.g. "91" corre‐
sponds to 1356 lbs (615 kg)).
The load-bearing capacity of the tire must be at
least half the gross axle weight rating of your
vehicle. Do not overload the tires by exceeding
the specified load limit.
See also:
Maximum permissible load on the Tire and
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Loading Information placard (
/
Maximum tire load ( page 368)
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Load index
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Speed rating 7 7 :
Specifies the approved maximum speed of the
tire.
% An electronic speed limiter prevents your
vehicle from exceeding a speed of 130 mph
(210 km/h).
Make sure that your tires have the required
speed rating. You can obtain information on the
required speed rating from an authorized
Mercedes-Benz Center.
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)
page 362)
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)