What Car? Q&A - Is it illegal not to have a spare wheel?

Q: I took delivery of a new Audi TT last week, but have just noticed that it doesn't have a spare wheel. I called the salesman to complain, but he said it isn't supposed to have one, and that I can seal punctures temporarily by injecting a type of foam into the tyre. Is this true? I would have thought it was illegal to sell a car without a spare.
Ross Murray

A: There isn't a specific legal requirement for car companies to include a spare wheel with a vehicle.

The only law regarding spare wheels is that, if you carry one and have to use it, it must pass all the laws relating to a car's other tyres, such as tread depth (1.6mm across the central three-quarters of the tyre's tread), condition and use.

More and more cars and being sold without spare wheel, and instead come with a can of tyre sealant. This saves space and reduces weight, but if you have a big puncture or blow-out it won't be any use and you’ll have to call out your breakdown service.

Some premium cars are also fitted with run-flat tyres. Run-flat tyres don't deflate in the same way as conventional tyres when punctured, and normally allow you to drive at limited speeds so that you can get to your nearest tyre fitter.