Key takeaways
- The load index is the number just before the speed letter, such as the 91 in 205/55 R16 91V.
- It is a code, not a weight in kilograms: 91 equals roughly 615kg per tyre, and higher numbers mean a higher capacity.
- You must fit tyres that meet or exceed the load index your vehicle specifies, which matters most on vans, SUVs and loaded cars.
- A reinforced or XL tyre carries a higher load index to suit heavier vehicles, marked XL on the sidewall.
- Fitting a lower load index than required can be unsafe, an MOT concern and may affect insurance.
The load index is one of the least understood markings on a tyre, yet it is one of the most important for safety. It tells you how much weight each tyre is built to carry, and fitting one rated too low can overload the tyre. This guide explains what the number means, how to read it against a chart, and why vans, 4x4s and loaded cars need particular attention.
What is the tyre load index?
The tyre load index is a numerical code showing the maximum weight a single tyre can carry at its rated pressure. It sits just before the speed rating, for example the 91 in 205/55 R16 91V. The number is not a weight in kilograms but a code that maps to one, with higher numbers meaning a higher carrying capacity.
Each tyre on the car carries part of the vehicle's weight, plus passengers and luggage. The load index makes sure the tyre can handle its share with a safety margin. Your vehicle's handbook specifies a minimum load index, and you should always meet or exceed it when buying replacements.
How do you read the load index number?
You read the load index against a standard chart, because the code does not directly state the weight. For example, 91 equals about 615kg per tyre, while 95 is around 690kg and 100 is around 800kg. Each step up the index adds carrying capacity. The table below shows common car and van values.
| Load index | Max load per tyre | Typical fit |
|---|---|---|
| 84 | 500 kg | Small hatchbacks |
| 88 | 560 kg | Compact cars |
| 91 | 615 kg | Family cars |
| 95 | 690 kg | Larger cars, estates |
| 100 | 800 kg | SUVs, light loads |
| 104 | 900 kg | 4x4s, loaded cars |
| 109 | 1,030 kg | Vans |
To find your car's total tyre capacity, multiply one tyre's figure by four. The combined figure must comfortably exceed the vehicle's fully laden weight, which is why matching the specified index matters rather than guessing from the size alone.
Why does the load index matter most on vans and SUVs?
The load index matters most on heavier vehicles because they carry far more weight, often with bulky loads. A van or large SUV needs a much higher index than a small hatchback, and getting it wrong risks overloading the tyre, causing overheating and a higher chance of failure. This is why vans usually carry reinforced tyres.
Loaded cars matter too. Fill the boot, add a roof box and four passengers, and the weight on the tyres rises sharply. The specified load index already accounts for the vehicle's maximum, so meeting it keeps a safety margin even fully laden. On a van that earns its living, the correct index is essential, not optional.
What are XL and reinforced load ratings?
XL stands for extra load, a tyre built with a stronger structure to carry more weight at a higher pressure than a standard tyre of the same size. It is marked XL or Reinforced (RF) on the sidewall and carries a higher load index. Many SUVs, vans and heavier cars specify XL tyres as standard.
If your car came with XL tyres, you should replace them with XL tyres, not standard ones, even in the same size. The stronger construction is there for a reason. Our dedicated guide on XL and reinforced tyres explains the difference in more detail and when you need them.
Can you fit a higher load index?
Yes, fitting a higher load index than required is generally fine and sometimes sensible. A higher index simply means more carrying capacity, so it exceeds the specification safely. The only thing to watch is that a much stiffer, higher-rated tyre can slightly firm up the ride, though the difference is usually small on an ordinary car.
What you must not do is fit a lower load index than your vehicle specifies. An under-rated tyre can be overloaded in normal use, which causes heat build-up and raises the risk of failure. It can also be flagged at MOT and may affect your insurance, so always meet or beat the required figure.
Matching the right tyres
When you replace tyres, match the load index and speed rating on your current tyres or in the handbook, alongside the size. The tyre numbers guide walks through the whole code, and the speed rating guide covers the letter that follows the load index. When you need correctly rated tyres fitted, Fast Tyre brings mobile tyre fitting to your home, work or roadside across London and central England, matching the right load index for your car or van.
Frequently asked questions
It is a numerical code showing the maximum weight one tyre can carry at its rated pressure. The number sits just before the speed letter, such as 91 in 205/55 R16 91V. Higher numbers mean a higher carrying capacity, and you should match your vehicle's specified index.
A load index of 91 means each tyre can carry about 615kg at full pressure. Across four tyres that is roughly 2,460kg of total capacity. The combined figure must comfortably exceed your vehicle's fully laden weight, which is why matching the specified index matters.
No. A lower load index than your vehicle specifies can be overloaded in normal use, causing heat build-up and a higher risk of failure. It can also be flagged at MOT and may affect insurance. Always fit tyres that meet or exceed the required index.
XL means extra load, a tyre built with a stronger structure to carry more weight at a higher pressure than a standard tyre of the same size. It carries a higher load index and is marked XL or Reinforced. Many SUVs and vans require XL tyres.
Yes. Vans carry far more weight than cars, often with heavy loads, so they need a much higher load index, usually with reinforced or XL construction. Fitting an under-rated tyre risks overloading and failure, so van tyres should always meet the specified rating.
No, fitting a higher load index than required is generally fine, as it simply adds carrying capacity. A much stiffer, higher-rated tyre can slightly firm up the ride, but the difference is usually small. Just never go below the load index your vehicle specifies.