1. P indicates that the tire is for passenger vehicle use.

2. The width of the tire from sidewall edge to sidewall edge in millimeters.

3. The aspect ratio, also known as the profile, gives the sidewall height as a percentage of the tread width. So, if the tread width is 205 mm and the aspect ratio is 50, the sidewall height will be 102 mm.

4. R indicates that the tire is of Radial ply construction.

5. The diameter of the wheel rim given in inches.

6. The load index for the tire. This index is not always shown.

7. The speed rating denotes the maximum speed at which the tire should be used for extended periods. See 194, SPEED RATINGS.

8. U.S. DOT Tire Identification Number (TIN). This begins with the letters DOT and indicates that the tire meets all federal standards. The next 2 numbers or letters are the plant code where the tire was manufactured, the last 4 numbers are the date of manufacture. For example, if the number was 3109, the tire was made in the 31st week of 2009. The other numbers are marketing codes used at the manufacturer’s discretion. This information can be used to contact consumers if a tire defect requires a recall.

9. M+S or M/S indicates that the tire has been designed with some capability for mud and snow.

10. The number of plies in both the tread area, and the sidewall area, indicates how many layers of rubber coated material make up the structure of the tire. Information is also provided on the type of materials used.

11. Wear rate indicator. A tire rated at 400 for example, will last twice as long as a tire rated at 200.

12. The traction rating grades a tire’s performance when stopping on a wet road surface. The higher the grade, the better the braking performance. The grades, from highest to lowest are; AA, A, B and C.

13. The maximum load which can be carried by the tire.

14. Heat resistance grading. The tire’s resistance to heat is grade A, B or C, with A indicating the greatest resistance to heat. This grading is provided for a correctly inflated tire, which is being used within its speed and loading limits.

15. The maximum inflation pressure for the tire. This pressure should not be used for normal driving.