The Code to Know

  What do the numbers on tires mean?

The tire size “P205/75R14 957 M&S Traction A Temperature B” may not mean much to the average individual, but to technician like us it speaks volumes. Learn how to crack the tire code with this short guide dedicated to tire types, sizes, and construction.

The first letter indicates the intended use or vehicle class for the tire. In this instance P is for passenger car. Other optional letters would be LT is for light truck, ST is for special trailer and T is for temporary is would be found mostly on spare tire for “space-saver”

Traction and temperature grades. The traction grade is the tire’s ability to stop under control conditions on wet pavement. The traction grades from highest to lowest are AA, A, B, and C. These gradings are base on straight-ahead braking test.

Temperature grades represent the tire’s resistance to heat and its ability to dissipate when tested under controlled test. The temperature from highest to lowest are A, B, and C. The temperature grade is established for a tire that is properly inflated and under normal load conditions.

There are other typical tire marking, these may include M&S indicating that the tire meets the average traction in muddy or very snowy conditions. These marking are commonly found on all-season tires. For more info click here.