Temperature A, B, C
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 Standards No. 109. Grades B and A represent higher levels of performance on the laboratory test wheel than the minimum required by law.

The temperature grade for this tire 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.
See also:
Tire chains
CAUTION
Tire chains cannot be used on any tires for your Legacy and Outback because of
lack of clearance between the tires and vehicle body. ...
Recommended grade and viscosity
Each oil manufacturer has its own base oils and additives. Never use different brands together. For details, refer to “Manual transmission, front differential and rear differential gear oil”. ...
Types of tires
You should be familiar with type of tires present on your vehicle. ...
