Anyone interested in the merits – or otherwise – of run-flat tyres, would have done well to catch the Car Clinic column of the Sunday Times’ brilliant ingear driving supplement.
NS from Uttoxeter, Staffordshire, posed this question: “I am choosing a new car and some of my options come with run-flat tyres. Are these better than normal tyres and, if so, why doesn’t everyone fit them?”
Dave Pollard, the extremely well-informed member of the Car Clinic panel who has tested virtually every car-related accessory, had this response: “Run-flat tyres have extremely strong side walls so the tyre does not collapse if punctured, typically giving you 50-150 miles to drive to a garage for a replacement, though at a reduced speed.
“There are great safety benefits, not least that a car fitted with run-flats should still be controllable even after a blowout at speed. You don’t have to stop and repair a puncture by the roadside, nor do you need to carry a spare tyre, which frees up space and makes the car a little lighter.
“The innovation comes with a compromise, though. The strong side walls make for a harder ride than usual, so the car is generally less comfortable. Run-flat tyres also tend to be more expensive to replace.
“Developments in technology mean that these drawbacks are becoming less noticeable. Bridgestone’s third-generation run-flat tyres, which are slowly coming on to the market, are claimed to provide a better ride quality, because of a softer side wall that absorbs more jolts but can still support a deflated tyre.
“The technology has been around for about 40 years but it is only recently that it has become anything like popular, mainly because of the efforts of BMW, which has made them standard issue on most models for several years, despite vociferous complaints from some customers about poor ride quality. There is still some way to go, though. Figures from Bridgestone suggest that run-flats account for only about 3% of the market.
“Test drive cars fitted with both types of tyres before you buy, because vehicles designed for one type should not be used with the other.”