Temperature 

Temperature grades are an indication of a tire's resistance to heat. Sustained high temperature (for example, driving long distances in hot weather), can cause a tire to deteriorate, leading to blowouts and tread separation. From highest to lowest, a tire's resistance to heat is graded as “A”, “B”, or “C”.

Of current tires:

• 27% are rated “A”
• 59% are rated “B”
• 11% are rated “C”