Load and speed ratings on a van, and why they are not optional

Same size is not the same tyre

A van and a car can take the identical size — same width, same profile, same rim — and need completely different tyres. The difference is the load index and the construction behind it.

A commercial tyre has a stiffer casing and a higher load rating because the vehicle spends its life carrying weight. The car equivalent in the same size does not.

The plate is the authority

Every van has a plate giving the maximum axle weights and the required tyre ratings. That is the figure, not whatever is currently fitted.

We check it on every commercial job, because the wrong tyre fitted by somebody else is one of the most common faults we find.

If the load rating is below the plate, it is an MOT failure. It is also a tyre doing a job it was not built for.

Why it happens

Usually price. A car tyre in the same size can be substantially cheaper, and a fitter who does not check the plate can sell one without ever knowing.

Occasionally it is stock: the right tyre was not on the van, and somebody fitted what was.

What goes wrong

Not usually a dramatic failure on day one. What happens is the tyre runs hotter than it should when loaded, wears unevenly, and fails earlier — often on a motorway with a full load, which is the worst time.

It also affects how the van handles under braking, which the driver notices as vagueness rather than as a fault.

XL, C and reinforced

A C-rated tyre is a commercial one. XL or reinforced means a higher load capacity than standard for that size. Neither is interchangeable with a standard car tyre.

If you are not sure what is on your van, send us the registration and we will tell you what should be.

How to check what you have

The plate first: door shut or under the bonnet, giving axle weights and the required ratings. Then the sidewall of what is actually fitted, and compare.

If the fitted load index is lower than the plate demands, it is wrong regardless of how long it has been on there or who put it there.

Send us the registration if you would rather not work it out. It takes us a minute and there is no charge for the answer.

The most common wrong tyre we find was fitted by somebody who never looked at the plate.

What the right tyre costs

Usually fifteen to thirty per cent more than the car equivalent in the same size. That gap is the whole reason the wrong ones get fitted.

Against that, a commercial tyre on a loaded van lasts longer than a car tyre being overworked, so the cost per mile is frequently lower rather than higher.

And the MOT failure costs a retest plus the tyre you should have bought in the first place.