Understand what your tires can carry
Load index, load range, SL, and XL
Load index is a capacity code for one tire under specified conditions. Load range and XL describe something different. Here is how to keep them straight.
Turn the load-index number into a capacity
In 102H, 102 is a reference code, not a weight in pounds. A load-index table maps 102 to 850 kg, or 1,874 lb, for one tire under specified conditions. That capacity depends on the tire’s application and inflation requirements. Use the exact tire’s published specifications; a number on the sidewall does not tell you what pressure to put in your vehicle.
SL, XL, and load range: three markings to recognize
SL means Standard Load and XL means Extra Load. An XL tire can support a higher maximum load than a comparable SL tire of the same size when used under the specified inflation conditions. Light-truck tires may use load ranges such as C, D, or E. These identify load/inflation capability. A 10-ply rating describes a strength category, not necessarily ten physical layers.
A tire rating does not increase the vehicle’s capacity
Follow the vehicle placard, owner’s manual, axle limits, and tire manufacturer’s data. A higher-rated tire does not raise the vehicle’s payload or towing limits. Never choose a replacement below the required capacity; have an installer confirm changes in tire construction or load range.
Selected load-index examples for one tire under its specified inflation conditions. These do not change your vehicle’s payload limit.
- Index 91615 kg / 1,356 lb
- Index 94670 kg / 1,477 lb
- Index 98750 kg / 1,653 lb
- Index 102850 kg / 1,874 lb
- Index 104900 kg / 1,984 lb
Your quick reference
| Marking | Describes | Does not tell you |
|---|---|---|
| Load index | A table-based capacity for one tire | The vehicle’s permitted payload |
| SL / XL | Standard or Extra Load construction | The correct vehicle tire pressure |
| Load range | Light-truck load/inflation capability | A literal count of plies |
Common questions
Is load index the same as load range?
No. Load index is a numerical capacity code for one tire. Load range describes a load/inflation category commonly used for light-truck tires. Check both when the tire lists them.
Will XL tires let my vehicle carry more?
Changing tires does not raise the vehicle’s payload, axle, or towing limits. XL describes the tire’s load/inflation capability; the vehicle’s limits still apply.
Does a higher load index mean I should add more air?
No. Do not choose pressure from the index alone. For the approved setup, use the vehicle’s cold-pressure recommendation. If you change tire size or construction, have a qualified installer confirm the appropriate load and inflation requirements.
Remember
Use the exact tire’s published specifications and the vehicle’s requirements together.
Sources & further reading
- Michelin: tire load ratings ↗ (opens in a new tab)
- Michelin: load-index reference chart ↗ (opens in a new tab)
- USTMA: load range and ply ratings ↗ (opens in a new tab)
Use this guide to understand the terminology. Follow your vehicle’s owner’s manual, tire placard, and the tire manufacturer’s instructions for your exact application.