Honda 1992 Accord Coupe Owner's Manual page 153

DOT Tire Quality Grades (cont'd)
Temperature
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 B and A represent higher levels of performance on
the laboratory test wheel than the minimum required by law.
The tire temperature grade is established for a tire that is properly
inflated and not overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination, can cause
heat buildup and possible tire failure.