To read a tire, focus primarily on the information printed on its sidewall, which includes tire size, construction, load capacity, speed rating, and manufacturing date.
How to Read Tire Size
Tire size is usually displayed in a format like P215/65R15 :
- P : Tire type (P = passenger car, LT = light truck, T = temporary/spare)
- 215 : Tire width in millimeters (measured from sidewall to sidewall)
- 65 : Aspect ratio, the height of the sidewall as a percentage of the width (65% of 215 mm)
- R : Radial construction of the tire
- 15 : Diameter of the wheel (rim size) in inches the tire fits
For example, a tire marked 215/65R15 means the tire is 215 mm wide, the sidewall height is 65% of 215 mm, it has radial construction, and fits a 15-inch wheel.
Additional Sidewall Information
- Load Index : A number indicating the maximum load the tire can carry.
- Speed Rating : A letter indicating the maximum speed the tire can safely sustain.
- Treadwear, Traction, and Temperature Ratings : These provide information on tire durability, grip on wet surfaces, and heat resistance, respectively
How to Read Tire Age
Look for the DOT code on the sidewall. The last four digits indicate the week and year the tire was manufactured:
- The first two digits of these four represent the week of the year (01 to 52).
- The last two digits represent the year.
For example, a DOT code ending in 3815 means the tire was made in the 38th week of 2015
Summary
- Check tire size: width (mm), aspect ratio (%), construction (R), and rim diameter (inches).
- Identify tire type (P, LT, etc.).
- Note load and speed ratings for performance and safety.
- Confirm tire manufacturing date via the DOT code to ensure tire age is safe for use.
This information helps ensure you select the right tire size and type for your vehicle and assess tire condition and safety
