Stopping distances and tyre wear

Many of us are aware that stopping distances can be affected by many things such as the weather, tyre wear and tyre pressures but yet you may not realise exactly how much tyre condition can affect the time it takes your vehicle to stop.

The law states that tyres must have at least 1.6mm of tread in a continuous band around the centre three quarters of the tyre, anything below this is classed as illegal and can cost you a fine and three points on your license per tyre. Although this is what the laws states, many mechanics and tyre fitters stress that really tyres should be replaced when they reach 3mm of tread. A new tyre starts off with 8mm of tread but once it gets to 3mm of tread, braking distances are affected greatly.

At a speed of 50mph a car fitted with tyres with 3mm of tread will usually stop in 31.7 meters, a car with only 1.6mm (the legal limit) can take 39.9 meters to stop, over 8 meters more. In an emergency braking situation this could be the difference between stopping in time and not. In the wet on the motorway a car with tyres with only the legal limit of tread left on can take 44 meters to stop, which will often result in it running in to another vehicle.