Every tire has a series of numbers and letters on its sidewall, but most drivers don’t understand what they mean. These codes provide crucial information about the tire’s size, type, load capacity, speed rating, and manufacturing details. In this guide, we’ll break down each number and letter so you can make informed decisions when buying or maintaining your tires
1. Tire Size Breakdown (Example: P215/65R16 95H)
Let’s decode a common tire size marking: P215/65R16 95H
| Code | Meaning |
|---|---|
| P | Type of Tire – “P” stands for Passenger vehicle (others: “LT” = Light Truck, “T” = Temporary spare). |
| 215 | Tire Width – The width in millimeters from sidewall to sidewall (215 mm). |
| 65 | Aspect Ratio – The height of the sidewall as a percentage of the width (65% of 215 mm). |
| R | Construction Type – “R” means Radial (most modern tires). Others: “D” (Diagonal/Bias-ply). |
| 16 | Wheel Diameter – The size of the wheel rim in inches (16 inches). |
| 95 | Load Index – Maximum weight capacity per tire (95 = 1,521 lbs). |
| H | Speed Rating – Maximum safe speed (H = 130 mph). |
2. Load Index (What Does the Number Mean?)
The Load Index indicates how much weight a tire can safely support. Higher numbers mean greater load capacity.
| Load Index | Max Load (lbs per tire) |
|---|---|
| 85 | 1,135 lbs |
| 90 | 1,323 lbs |
| 95 | 1,521 lbs |
| 100 | 1,764 lbs |
| 110 | 2,337 lbs |
Example: A tire with a 95 Load Index can carry 1,521 lbs per tire
3. Speed Rating (What Does the Letter Mean?)
The Speed Rating shows the maximum speed a tire can handle under optimal conditions.
| Speed Symbol | Max Speed (mph) | Typical Use |
|---|---|---|
| L | 75 mph | Off-road tires |
| T | 118 mph | Family sedans |
| H | 130 mph | Sport sedans/coupes |
| V | 149 mph | Performance cars |
| W | 168 mph | High-performance sports cars |
| Y | 186 mph | Supercars |
Example: A tire with an H rating is safe up to 130 mph.
4. DOT Code (Manufacturing Date)
The DOT code shows when the tire was made. The last four digits indicate the week and year of production.
- Example: DOT XXXXXX 2523 → 25th week of 2023 (June 2023).
- Tires older than 6 years should be inspected, even if tread looks good.
5. Other Important Tire Markings
✔ M+S (Mud & Snow) – Suitable for winter/all-season use.
✔ 3PMSF (Three-Peak Mountain Snowflake) – Certified for severe snow conditions.
✔ Max Load / Max Pressure – Maximum weight and air pressure limits.
✔ Treadwear Number (e.g., 400) – Higher numbers mean longer tread life (compared to a baseline of 100).
Why Understanding Tire Numbers Matters
- Ensures you buy the correct size for your vehicle.
- Helps maintain safety and performance.
- Prevents overloading or speed-related tire failure.
Final Thoughts
Next time you check your tires, take a closer look at the sidewall numbers. Knowing what they mean can help you choose the right tires, maintain proper inflation, and drive safely.
Need new tires? Match these numbers with your vehicle’s requirements for optimal performance!
