Tyres can be no wider than at the rear, front tyre width expanded from 245 mm to 305 mm for the 2017 season. Unlike the fuel, the tyres bear only a superficial resemblance to a normal road tyre. Whereas a road car tyre has a useful life of up to , a Formula One tyre does not even last the whole race distance (a little over ); they are usually changed one or two times per race, depending on the track. This is the result of a drive to maximize the road-holding ability, leading to the use of very soft compounds (to ensure that the tyre surface conforms to the road surface as closely as possible).