P-Metric Sized Tires

Most P-metric tires do not have exact corresponding alpha-numeric tire sizes. For example, a P205/75R15 is not equal in size and load carrying capacity to an FR78-15. For this reason, replacement tires should be of the same TPC specification number (size, load range, and construction) as those originally on the vehicle. If P-metric tires must be replaced with other sizes, a tire dealer should be consulted. Tire companies can best recommend the closest match.

Bias-ply tires are identified by the numerical designations of the tread width (in inches) and the bead/rim diameter (in inches) (FR78-15).
Radial-ply tires are identified by the letter R or Radial on the side wall. The tire type, size, aspect ratio are encoded (e.g., P205/75R15) on the side wall.
- P indicates passenger car, LT for light trucks.
- 205 is the section width of the tire.
- R designates radial type design construction.
- 75 is the aspect ratio (height to width ratio).
- 15 is the rim diameter in inches. An All Season tire will have either M+S, M&S, or M-S imprinted on the side wall.