Michelin claim no link between car tyre treads at 1.6mm and increasing accident rates. They say that changing tyres at 3mm would cost the motorist money and increased carbon emissions - especially as a tyre becomes more fuel efficient as it wears.
They even commissioned Ernst & Young, who reported that changing tyres at 3mm instead of 1.6mm would cost drivers an extra 6.9 billion a year in unnecessary purchases and additional fuel consumption.
Yet RoSPA, Continental Tyres and several other outlets say 3mm is the minimum for safety. MIRA tests back this up. Some also point out that tyre grip when cornering isn similarly affected. I haven't found any other source that supports Michelin's views.
Many sites do warn of the legal implications. Being caught with a tread depth that can be measured to be under 1.6mm renders the driver to fines of up to £2,500 and 3 penalty points - and that is PER tyre.
If 1.6mm is truly safe, why could 1.5mm carry such a hefty penalty?
Personally, and although I do run on Michelin Energy tyres, I will continue to change my tyres at 3mm tread depth. The carbon emission factor is a red herring - providing that the discarded 3mm tyres are properly recycled they present no more risk than 1.6mm tyres. In fact, the 1.6mm tyres have been allowed to discharge more carbon into the environment because of their extra wear. The 1.6mm tyre will have a smaller rolling radius, meaning more rotations/mile, and more likely to "scuff" from stationary, so mpg could be adversely affected in both cases.
They even commissioned Ernst & Young, who reported that changing tyres at 3mm instead of 1.6mm would cost drivers an extra 6.9 billion a year in unnecessary purchases and additional fuel consumption.
Yet RoSPA, Continental Tyres and several other outlets say 3mm is the minimum for safety. MIRA tests back this up. Some also point out that tyre grip when cornering isn similarly affected. I haven't found any other source that supports Michelin's views.
Many sites do warn of the legal implications. Being caught with a tread depth that can be measured to be under 1.6mm renders the driver to fines of up to £2,500 and 3 penalty points - and that is PER tyre.
If 1.6mm is truly safe, why could 1.5mm carry such a hefty penalty?
Personally, and although I do run on Michelin Energy tyres, I will continue to change my tyres at 3mm tread depth. The carbon emission factor is a red herring - providing that the discarded 3mm tyres are properly recycled they present no more risk than 1.6mm tyres. In fact, the 1.6mm tyres have been allowed to discharge more carbon into the environment because of their extra wear. The 1.6mm tyre will have a smaller rolling radius, meaning more rotations/mile, and more likely to "scuff" from stationary, so mpg could be adversely affected in both cases.