Understanding tire specifications is crucial for ensuring safety and performance. The tire load index chart provides information about the tire’s load-bearing capacity, helping you choose the right tire for your vehicle’s load. This article explains the load index and speed rating in detail, along with a quick and accurate lookup table.
The load index and speed rating are usually marked on the tire sidewall, for example, “91W”. The number “91” is the Load Index, and the letter “W” is the Speed Rating.
What is Load Index?
The Load Index is a number indicating the maximum load a tire can carry at a specified pressure and speed. The higher the number, the greater the load-bearing capacity of the tire. The tire load index chart below will help you convert the load index to a specific weight (kg).
Tire Load Index Chart:
| Load Index | Kg | Load Index | Kg | Load Index | Kg | Load Index | Kg |
|---|---|---|---|---|---|---|---|
| 51 | 195 | 81 | 462 | 111 | 1090 | 141 | 2575 |
| 52 | 200 | 82 | 475 | 112 | 1120 | 142 | 2650 |
| … | … | … | … | … | … | … | … |
| 120 | 1400 | 150 | 3350 | 180 | 8000 | 210 | 19000 |
| … | … | … | … | … | … | … | … |
| 250 | 60000 |
Truck and commercial vehicle tires usually have a higher load index than passenger car tires due to the requirement to transport heavy goods.
What is Speed Rating?
The Speed Rating is a letter indicating the maximum speed a tire can withstand under specified load conditions. The closer the letter is to the end of the alphabet, the higher the maximum allowable speed.
Tire Speed Rating Chart:
| Speed Rating | Km/h | Speed Rating | Km/h |
|---|---|---|---|
| L | 120 | V | 240 |
| M | 130 | W | 270 |
| … | … | … | … |
| Y | 300 | (Y) | 300+ |
For tires with a speed rating of Y (above 300km/h), manufacturers are required to add the symbol Z to the tire size.
Significance of the Tire Load Index Chart
Consulting the tire load index chart and speed rating helps you:
- Choose the right tires: Ensure the tires meet the load and speed requirements of your vehicle.
- Operate safely: Avoid overloading the tires or operating beyond the allowable speed, which can be dangerous.
- Optimize performance: Suitable tires help the vehicle run smoothly, save fuel, and extend tire life.
When replacing tires, ensure that both the size and these two indexes match the inspection certificate to ensure safety and insurance benefits. Exceeding the maximum load or speed can affect the performance and safety of the vehicle. Refer to your vehicle’s owner’s manual for the load and speed ratings recommended by the manufacturer.
