Is an illegal spare tyre an MOT failure?

illegal spare wheel

The spare tyre is increasingly a thing of the past. But are there still rules and regulations for those cars that do carry them? And what if your car has a space saver spare wheel? Must it be inflated to the right level and have a legal tread depth? Read on to find out.

Do you need to carry a spare wheel?

There is no requirement in the law for a car to carry a spare wheel, or indeed any means of addressing a puncture. The RAC estimates that nine out of 10 new cars no longer come with a spare wheel as standard. The spare has been superseded by either run-flat tyres or puncture repair kits.

If you do carry a spare, must it be legal?

A spare wheel doesn’t have to be legal. Spare wheels and tyres are NOT inspected in the MOT test. That goes for full-size spare wheels as well as space savers. But consider this: if you do have a spare wheel and it’s illegal, what happens if you need to use it? In getting going again after a puncture you’re making your car be considered unroadworthy. And driving a car with one illegal tyre can result in a £2,500 fine and three penalty points on your licence.

illegal spare wheel
If you carry a spare wheel it doesn’t have to be legal, but it helps (Picture iStock/Picture©TyreSafe)

What makes a tyre illegal?

Tyres are tested by the MOT in four areas: condition, security, size and type, and tread depth. MOT testers will inspect road tyres closely for lumps, cuts and other damage such as punctures by foreign bodies. They will also look at how securely wheels are fitted to the car.

Size and type of tyre is important. You can’t mix and match the tyre of tyre (radial or crossply) or wheel sizes on the same axle.

But the most likely reason for a spare tyre to fail the MOT is because it doesn’t have sufficient tread depth. A tyre must have 1.6mm of tread across central three quarters of the treaded area.

What if the tester notices an illegal spare?

Government guidelines for MOT testers say that they should alert whoever is presenting the vehicle for testing to the spare wheel problem.

What about using a space saver for the MOT test?

You must have four legal road tyres to pass the MOT. If you present your car with a space saver spare mounted on one hub, it will fail instantly.

What about if you’re driving on a space saver?

These wheels and tyres are thinner than regular tyres so your car won’t have the same stopping power as with four regular tyres. It’s estimated that driving on a space saver will reduce grip by 10 to 15%.

There is no finite distance you can use one for but you’re only recommended driving on a space saver for a maximum of 50 miles. Remember that space savers only have around 3mm of tread depth when they’re new. This compares to a regular tyre which will have 8mm when it leaves the retailer. The maximum speed you can drive at with most space savers is 50mph.