Temperature - THOR Class C Series Owner's Manual

T I R E S A N D W H E E L S
3
NOTE: NHTSA's tire rating listings are
located online at https://www.safercar.gov/
Vehicle-Shoppers/Tires-Rating.
NHTSA also has more tire information
located online at https://www.safercar.gov/
tires/index.html.
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Traction Grades
AA
A
B
C
Temperature – A, B, and C
The temperature grade is established for a tire that is properly inflated and not
overloaded. Excessive speed, under inflation, or excessive loading, either separately
or in combination, can cause heat buildup and possible tire failure.
The temperature grades are A (the highest), B, and C, representing the tire's resistance to the
generation of heat and its ability to dissipate heat when tested under controlled conditions on
a specified indoor laboratory test wheel. Sustained high temperature can cause the material of
the tire to degenerate and reduce tire life, and excessive temperature can lead to sudden tire
failure. The grade C corresponds to a level of performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety Standard No. 109. Grades A and B represent
higher levels of performance on the laboratory test wheel than the minimum required by law.
Temperature Grades
A
B
C
Asphalt g-Force Concrete g-Force
Above 0.54 0.41
Above 0.47 0.35
Above 0.38 0.26
Less Than 0.38 0.26
WARNING
Speed in Miles per Hour
Over 115 MPH
Between 100 and 115 MPH
Between 85 and 100 MPH
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