The load index and speed rating are the final numbers and letter in your tyre size, e.g. the "91V" in 205/55 R16 91V. The load index is the maximum weight the tyre can safely carry; the speed rating is the maximum speed it's designed for. Fitting a tyre rated lower than your car needs is unsafe and can fail the MOT.
Load index
The load index is a code that maps to a maximum weight per tyre. For example, 91 corresponds to 615kg per tyre. Heavier vehicles, vans and EVs need higher load indices, and many EVs use reinforced (XL) tyres for exactly this reason.
Speed rating
The speed rating is a letter representing the tyre's maximum design speed:
| Letter | Max speed |
|---|---|
| T | 118 mph |
| H | 130 mph |
| V | 149 mph |
| W | 168 mph |
| Y | 186 mph |
The rating isn't a licence to drive that fast, it reflects the tyre's construction and heat tolerance. Always match or exceed your car's specified rating.
Why it matters
An under-rated tyre can overheat and fail under load or at speed, and your insurer may treat an incorrectly rated tyre as a modification. When in doubt, use the rating on your existing tyres or the door-sill placard, and read the full sidewall markings guide.
We always fit the correct load and speed rating for your vehicle. Book a mobile fit across London and Birmingham.
