There is nothing in the law that says you have to carry a spare wheel so a lot of cars don’t have them in order to save weight. Instead these models usually come with tyre inflation kits that are designed to cope with a flat tyre. If your car doesn’t have one, it’s definitely worth thinking about getting one.

How do inflation kits work?

These usually come in two parts. There’s a compressor for pumping tyres up and mousse that comes with a nozzle adapter enabling you to inject it into the tyre through the valve. When you use the supplied compressor to pump the tyre up through the air hose, the mousse plugs the hole.

Are tyre inflation kits any good?

That depends on the kind of puncture you’ve had. If it’s a small hole in the central tread area, say caused by a nail, then yes, they should work. However, if you’ve hit an object and perhaps gashed the tyre’s sidewall, then an inflation kit is pretty useless.

It also depends on how quickly you’ve noticed the puncture and therefore stopped. If you’ve driven some distance with low tyre pressure, the tyre may well have overheated and shredded.

All that said, in certain circumstances, inflation kits are very good. They could well get you home and mean you don’t have to change the wheel. It’s something that might appeal to anyone who isn’t confident with a jack and wheel brace.

You can get aftermarket kits

If you like the sound of these, you can buy them over the counter from motor retailers or via the internet. They cost anywhere between about £6 and £30. However, if you buy one from the car maker, it’s likely to be pricier.

That said, you do get what you pay for and not all kits are the same. The key ingredient is the compressor and these vary in power. A high quality compressor will have more power. The more power a compressor has, the quicker it will re-inflate the tyre. It’s also worth checking how clear the gauges are and how long the air hose is. And a carrying case will ensure everything is kept together in the boot which will stop bits getting lost over time.

But they may mean you can’t repair the tyre

Sometimes punctured tyres can be repaired, depending on the position of the hole. It also depends on how far underinflated tyres have been driven without sufficient air. The more miles, the more damage that’s likely to occur to the tyre’s structure and the less likely it is a repairer will be able to work their magic. Read all about tyre repairs here.

It’s also worth remembering that the mousse used with inflation kits is by its nature sticky and fairly unpleasant stuff to deal with. Frequently fast fit operations will refuse to repair tyres because cleaning out the mousse to make the repair is too time consuming, messy and difficult.

You could always buy a spare

Unless it’s a specialist sportscar with no boot, or perhaps a model with two different sizes of tyre front to back, there will doubtless be a space in or under the boot for a spare wheel. And usually for around £100 you can buy a spacesaver spare from the manufacturer.

At least keep a locking wheel nut key

Most cars now have alloy wheels. And to prevent nerks nicking them for their 15-year old Corsas, car makers give them locking wheel nut keys. This means if you need to change a wheel, you’ll need a locking wheel nut key.

Of course with an inflation kit you shouldn’t need one at the roadside. But inflation kits do only offer a very temporary repair. And you will have to get the tyre changed at some point. Most breakdown organisations and garages have tools that will remove locking wheel nuts if you can’t find your key.