There are big differences between the best and worst new cars’ brakes, says Which? Car, after measuring the average distance new cars took to stop from 62mph.

In the supermini category, the Volkswagen Polo took 34.16 metres, whereas a Suzuki Alto took 42.52m - over 8m more.

The worst performing car in the test was an MPV - the Chrysler Grand Voyager at 43.49m. Other poor performers were the Mercedes A-class (bottom of the medium cars category at 41.61m) and the Land Rover Freelander (bottom of the 4x4 category at 42.04m).

Which? Car is pressing manufacturers to publish the average braking distances of their cars.

It’s difficult to get hold of this information at present, so the consumer watchdog has published the results of hundreds of new car models it tested at which.co.uk. The best and worst cars in each class are shown at www.which.co.uk/braketests.

Peter Vicary-Smith, chief executive, Which?, says: “Car manufacturers are good at telling us how quickly cars get from zero to 60 miles per hour, but they’re not so good at telling us how quickly they get from 60 to zero. We think people should have this information before deciding whether to buy a car. This could be a matter of life and death.”