Fashion has followed performance, which is why ultra low-profile tyres have become more common. Every car tyre has an aspect ratio, which is a comparison of its height in relation to its width. A ‘full profile’ tyre has a section height that is 80 to 85 percent of its width; such tyres are rarely seen these days, unless a classic vehicle is riding on them.
Aspect ratios have been falling over the years. 70 percent profiles came along, followed by 65 percent, 60 percent and so on. Nowadays, 45 percent profile tyres can be seen on high-performance cars and the current low figure is a mere 35 percent. Beware though, ultra-low profile tyres may look thrilling and they certainly offer tremendous performance. There is, however, a twofold cost. The lower you go, the more ride comfort suffers. What’s more, wheel damage from touching a kerb, or hitting a pothole or debris in the road, is far more likely.
Formula One Facts
A Formula One car can accelerate from rest to 99.42 miles per hour and decelerate back to zero in four seconds. Even though such a car weighs only a little over half a tonne, the breathtaking forces involved clearly give the tyres a hard life. Here are some captivating facts from F1′s sole tyre supplier, Bridgestone.
The company produces 40,000 of its Potenza F1 tyres each year and takes 1,800 tyres to each grand prix.
During the 2008 grand prix season, 19,435 laps were completed on Potenza F1 tyres.
A Bridgestone tyre fitting team can fit 56 car tyres per hour, that’s 14 sets of tyres. Sixty of the company’s personnel attend each grand prix, taking with them 12 tonnes of specialised equipment.
At just over 186 miles per hour, Bridgestone wet weather tyres displace 61 litres of water per second.
Potenza F1 tyres are built to last – for around 93 to 124 miles under racing conditions.
Back to the Real World
Now for some less esoteric facts and figures, from the everyday world of motoring.
About 75 percent of British motorists are driving on under-inflated car tyres.
What this is doing to their carbon footprints isn’t known but it is costing them over 2 billion pounds every year.
Approximately 12 per cent of the cars in the UK have at least one defective tyre.
Another 12 percent have a tyre with less than two millimetres of tread, which is legal but decidedly unsafe.
Ninety percent of Britain’s motorists don’t know the pressure to which their tyres should be inflated.
Continental Tyres carried out a study, which discovered that 40 per cent of British motorists claim never to have checked the pressure in their car tyres.
More than 40 per cent of drivers admitted that they didn’t know how to check tyre tread depth. Seventy per cent had no idea of the legal minimum tread depth, which is 1.6 millimetres over 75 per cent of the tread’s width, in a continuous band.
About 20 percent of drivers confessed to driving on tyres that would probably not meet legal tread limits.
These sobering figures, apart from highlighting the need for a certain amount of education for UK drivers, suggest something else. It’s comforting that the average UK driver isn’t in charge of Formula One car tyres!