The spare wheel versus repair kit debate is one that gets many drivers revving like a racing engine, particularly if they’re buying a new car. The majority of new motors ‑ nine out of 10 according to website Honest John ‑ are sold without a full-size spare wheel. In most cases the spare is replaced with a repair kit that is designed to get you back on the road and to somewhere where you can buy a replacement tyre.
A flat tyre is likely to afflict every driver at some point in their motoring life. Changing wheels is the second most popular reason that customers call Green Flag out. And according to tyre maker Continental, drivers suffer a puncture on average every 44,000 miles or five years. So having something that can replace a flat tyre is clearly important. But in the spare wheel versus repair kit argument, which comes out on top? We investigate.
What’s wrong with the good old-fashioned spare wheel?
Car makers say they’re under increasing pressure to fit more equipment into cars. We take it for granted that they’ll have electric this and power-assisted that, in addition to air-conditioning and entertainment systems. All this kit takes up space. Throw in that petrol-electric hybrid cars frequently need the area under the boot to fit the petrol tank (the batteries now go where that usually lives) and in some cars there is simply no room for something that may never be used.
Why do drivers like them?
It’s undoubtedly reassuring to know that if you get a flat tyre, you can continue your journey with only the minor delay that a smooth wheel change can incur. But according to Continental, drivers who think that could be labouring under a misconception. The tyre maker claims that only 70 per cent of spare tyres are ever fitted when required. This is because many are underinflated, otherwise not fit to be used, or the driver can’t get the wheel off to change the tyre.
How do puncture repair kits work?
The kit includes a latex sealant that is forced into the tyre through the valve and a compressor. This runs off the car’s 12-volt power outlet and inflates the tyre. The theory is that the sealant will plug the hole when it’s put under pressure, enabling you to get home.
What are their benefits
Obviously weight and space weigh heavily on their side. These repair kits weigh a fraction of the 20kg a full-size spare wheel tips the scales at. And as they’re about half the size of a car battery, they take up a lot less space than a wheel. According to Continental, they will offer a temporary fix for four out of five punctures. And they will enable you to do 300-400 miles, thereby safely getting you off the roadside. Not having to mess about with a jack and wheel brace is a bonus too.
What are their disadvantages
For every one in five flat tyres they don’t work. For example, if you hit a kerb and cause significant damage to the sidewall of the tyre a repair kit won’t do the job. And if your tyre suffers a sudden structural failure – more commonly known as a blow out – they certainly won’t help. In addition, the inside of the tyre and wheel will be covered in a mousse like substance. Although they can be cleaned and repaired, contrary to what some say, many fitters will refuse because it’s such an unpleasant job.
What about space savers?
Around 25 per cent of new cars come with space savers. These are skinny wheels designed, as the name suggests, to cut down on the amount of room a spare takes up. Of course you still have to change the wheel. And once the space saver is on, your speed is limited to 50mph and range limited frequently to 50 miles, for safety reasons. On top of that, there’s every chance that the full-size wheel with the flat won’t fit in the spare wheel well.
And run flats?
These are also known as self-supporting tyres because they use the rigid sidewalls rather than air pressure to support the car if they’re punctured. Of course, you don’t have to change the wheel. And they’re so effective at disguising a puncture that some drivers have had to rely on their Tyre Pressure Monitoring System to discover their tyre had lost air pressure. However, the downside is that the ride can be on the firm side with these because of those rigid sidewalls.
Are self-sealing tyres the future?
This is a relatively new and increasingly popular innovation in the world of tyres. The tyres are fitted with an air-proof layer inside which seals punctures in the tread area. Richard Durance from Continental explained: “Our research shows 95 per cent of punctures are caused by objects up to 5mm in diameter. The self-sealing tyre will cope with that and you’ll be able to continue driving, probably without even knowing you’ve had a puncture.”
Spare versus repair? Let’s be honest, every one of these solutions feels like a compromise. But probably the best answer is the self-sealing tyre. However, there are still downsides. In this case you’re likely to pay a bit more for tyres that mend themselves. Whether that’s a worthy price for the convenience of never having to change a tyre again is a personal choice.