Convert load index to kg, speed index to km/h, and find minimum required load index from axle weight
| Load Index | kg (per tyre) | lbs |
|---|
| Speed Symbol | Max Speed (km/h) |
|---|
The Load Index is a numerical code that indicates the maximum weight a tyre can safely carry at its recommended pressure.
For example, a Load Index of 91 means the tyre can support 615 kg. Always match or exceed the vehicle manufacturer’s recommended Load Index.
Using tyres with too low a Load Index can cause overheating, structural damage, and safety risks.
It may also affect insurance claims and roadworthiness tests.
Afterall, it is illegal to install tyres that does not match the permitted weight of the vehicle axle.
The first value applies when the tyre is used in a single wheel configuration - one tyre per side of the axle.
The second value applies when the tyre is used in a dual wheel configuration - two tyres mounted side by side on each side of the axle.
E.g. a tyre with 136/134,
A Toyota Hiace 200 uses single wheel configuration, 136 applies.
A 5.5 tonne Isuzu have dual wheel configuration at the rear, 134 applies.
The Speed Index (or Speed Rating) is a letter code (e.g., H, V, W, Y) that shows the maximum speed a tyre can safely sustain under load.
Choosing a tyre with too low a apeed Index can reduce handling, cause overheating, and invalidate insurance. Higher ratings usually mean better grip and stability, but shorter tread life.
Always follow the vehicle manufacturer’s specifications. Do not mix tyres with different Load or Speed Indexes. Consider your driving environment: city driving may only require T or H, while performance cars need V or above.