In Europe, the minimum tread depth for normal car tyres is set at 1.6mm. Rules for winter tyres vary.
Nevertheless many of our tyre retailers have long held the belief that minimum tread depth should be increased in the interests of road safety, presumably in the wet when tread is most needed.
Such a move would have several consequences. The bars set into the grooves of every tyre are currently positioned at 1.6mm or thereabouts (tyre making is still not quite an exact science) so changing this would be awkward and certainly very costly for manufacturers. The life of the product would also be reduced although some retailers might see this as a benefit. Lastly, there would be an environmental cost should tyres be replaced more frequently than at present.
The new tyre manufacturers have long been wary of this particular retail-driven demand and for the very reasons I have stated. There is also a reluctance to admit that claims about tyre performance might not be consistent over the full life of the product in every case.
Now Michelin, Europe’s dominant manufacturer has come forward with a quite categorical statement in favour of the status-quo. We, they say “maintain that the current legal limit of 1.6mm is perfectly suited to modern motoring” and go on to oppose a change in the current law. Their rationale for this position is that ‘new’ tyres do not really exist in practice because they begin to be worn down from the moment they are first used; consistent performance should be delivered right down to that indicator bar set at 1.6mm.
So that is it then.