Just like the in-car cassette player, winding windows and car alarms that beeped when you pressed the key fob, the spare tyre could be no more.
Although many car owners might not like the lack of a spare in many modern cars – tyre manufacturers’ evidence suggests that our quality of life could actually be better without them.
According to tyre firm Continental, spare wheels are only effective in about 70 per cent of punctures because they’re either unroadworthy or drivers don’t have the right tools, strength or knowledge to change a wheel.
There is also the safety issue of actually being on the hard shoulder or next to a busy road trying to change a tyre.
The alternative, as you will know if you’ve delved beneath the boot floor of many new cars, is the diverse world of, in tyre industry talk, Extended Mobility Solutions. For the car makers, the necessity to offer anything that will get us home after a puncture is an evil one. After all, a spare wheel is heavy, rarely used, and takes up luggage space. For some manufacturers, such as Jaguar, the matter is complicated by the fact that two of its three models have different wheel widths front and rear.
The initial answer to these varying factors was the space-saver, a narrow temporary wheel that takes up about half the room of the traditional full-sized spare and is about 7kg lighter. They might look spindly and faintly ridiculous but they have become common – and their weight makes them easier to fit.
Alternatively there is the compressor. This can work in two ways. Either you get a space-saver that takes up less room by needing an air compressor to inflate it. Or you inject foam to seal the puncture and use the compressor to re inflate. This is how Continental’s Conti Mobility Kit works. It weighs only 1kg and, says the German firm, has about an 80 per cent success rate and can be used for up to 400 miles.
Only slightly less successful, and still more reliable than the traditional and bulky spare wheel and tyre, is the new kid on the block, the self-sealing tyre. This Continental invention employs an air proof layer inside the tyre. Richard Durance from Continental says: “Our research shows 95 per cent of punctures are caused by objects up to 5mm in diameter and 61 per cent by objects up to 3mm. The material inside the self-sealing tyre stops air escaping through the tread area.”
For the first year after being introduced, self-sealing tyres were used exclusively by Volkswagen. But that deal is now finished so expect them to be fitted to other marques soon. Other advantages are that these tyres can be mounted on standard rims, there are no speed restrictions and they don’t impair the car’s ride. You can’t always say the latter about the run-flat tyre.
Run-flat tyres are also known as “self-supporting” because they have a rigid sidewall which enables the driver to continue after a puncture. According to tyre industry research, they’re 100 per cent reliable. But the downside is regular tyres’ flexible sidewalls help cushion road imperfections. Therefore, cars with run-flat tyres sometimes have a much firmer ride than those on regular rubber, as owners of Minis and some older BMW’s will attest.
So which of these solutions is the best? Each involves a degree of compromise, but then the average driver does only get a flat tyre once every 44,000 miles or five years.
Whatever the answer, it seems car makers and drivers alike are finally accepting that carrying a full-sized spare for a generally rare occurrence is like always having a bulky first aid kit in your pocket.
Article sourced from The Telegraph