Index Speed rating
ZR...Y
1
up to 186 mph (300 km/h)
ZR...(..Y)
1
over 186 mph (300 km/h)
ZR
1
over 149 mph (240 km/h)
R
Specifying the speed rating as the "ZR" index
in tire code 4 is optional for tires up to
186 mph (300 km/h).
R
If your tire code 4 includes "ZR" and there is
no speed rating 7, nd out what the maxi-
mum speed is from the tire manufacturer.
R
If load-bearing index 6 and speed rating 7
are in brackets, the maximum speed rating of
your tire is above 186 mph (300 km/h). To
nd out the maximum speed, ask the tire man-
ufacturer.
All-weather tires and winter tires
Index Speed rating
Q M+S
2
up to 100 mph (160 km/h)
T M+S
2
up to 118 mph (190 km/h)
H M+S
2
up to 130 mph (210 km/h)
V M+S
2
up to 149 mph (240 km/h)
Winter tires bear the i snowake symbol and
fulll the requirements of the Rubber Manufactur-
ers Association (RMA) and the Rubber Association
of Canada (RAC) regarding the tire traction on
snow.
Load index 8:
R
No specication given: standard load (SL) tire
R
"XL" or "Extra Load": extra load tire or rein-
forced tire
R
"Light Load": light load tire
R
"C", "D", "E": a load range that depends on the
maximum load that the tire can carry at a cer-
tain pressure
Denition of terms for tires and loading
Tire structure and characteristics: describes the
number of layers or the number of rubber-coated
belts in the tire contact surface and the tire wall.
These are made of steel, nylon, polyester and
other materials.
Bar: metric unit for tire pressure. 14.5038 pounds
per square inch (psi) and 100 kilopascal (kPa) is
the equivalent of one bar.
DOT (Department of Transportation): DOT-marked
tires fulll the requirements of the
U.S. Department of Transportation.
Average weight of the vehicle occupants: the
number of vehicle occupants for which the vehicle
is designed, multiplied by 150 lb (68 kg).
Uniform Tire Quality Grading Standards: a uniform
standard to grade the quality of tires with regard
1
"ZR" stated in the tire code.
2
Or "M+Si" for winter tires.
346
Wheels and tires
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