Tire Speed Ratings and Temperature

Tire speed ratings are assigned to tires based on a series of test conditions. Some people see a tire speed rating and assume they can drive their vehicles as fast as the rating allows, anytime. Drivers often miss the fact that tire speed ratings are based on near optimal conditions-perfect temperatures, safe conditions, etc. Drivers in Texas won't get the same performance from a tire in the summer heat as a driver in Canada in the dead of winter. Remember that speed means an increase in heat as the tire rotates on the pavement. Add summer heat, road debris, and other variables to the equation and you get a big caution flag from the laws of physics--don't try to approach the maximum speed rating of your tires under these conditions, you may get a lesson about heat physics the hard way.