How to Read a Tire Size Code
Learn what every number, letter, and safety symbol on your tire's sidewall actually means.
P indicates Passenger car tire (LT = Light Truck, ST = Special Trailer). 225 is cross-section width in millimeters.
Sidewall height is 55% of the tire's 225 mm section width (123.75 mm / 4.87 inches).
Radial construction: internal cord plies run perpendicular at 90 degrees to the direction of travel.
Diameter of the metal wheel rim in inches that this tire is manufactured to mount onto.
Numerical code representing maximum load capacity at proper cold tire pressure (97 = 1,609 lbs / 730 kg per tire).
Maximum safe sustained highway velocity capability of the tire under full rated load.
Official Tire Speed Rating Chart
| Rating | Top Speed Limit | Typical Vehicle Application |
|---|---|---|
| Q | 99 mph (160 km/h) | Winter & Off-Road Tires |
| R | 106 mph (170 km/h) | Heavy Duty Light Trucks |
| S | 112 mph (180 km/h) | Family Vans & SUVs |
| T | 118 mph (190 km/h) | Standard Sedans |
| H | 130 mph (210 km/h) | Sport Sedans & Coupes |
| V | 149 mph (240 km/h) | Performance Vehicles |
| W | 168 mph (270 km/h) | High-Performance Sports Cars |
| Y | 186 mph (300 km/h) | Exotic & Supercars |
| (Y) | 186+ mph (300+ km/h) | Ultra High-Performance Tracks |
How to Find Tire Age: The DOT Date Stamp SAFETY ESSENTIAL
Every tire manufactured after 2000 has a 4-digit date code at the end of its DOT serial number (e.g. DOT XXXX 4223).
Tire manufacturers recommend replacing tires after 6 to 10 years regardless of remaining tread depth due to rubber oxidation and dry rot.