Michelin tests at Ladoux have shown that on wet roads, some worn tyres can perform as well as some new tyres, and that although the remaining tread depth is a factor in wet braking, the performance of the tyre, at all stages of its life, is more important.
Tyre performance is affected by many factors; casing design, materials, rubber compounds, tread design, shape of grooves and sipes etc. and these all affect how the tyre performs throughout the tyre’s life – right down to the legal tread wear limit. All tyres do not perform the same when new – and the differences in performance are more accentuated when that tyre is worn, according to their design.
Tyre labelling and European regulations have brought in minimum standards for tyre performance, and particularly for wet braking – one of the criteria measured by tyre labelling. Whilst all tyres legally sold in Europe meet this minimum standard when new, Michelin tests have shown that the wet braking capabilities of some tyres reduce quickly when worn, and may fall below this ‘minimum standard’ requirement. However, some premium products not only meet the criteria when new, they do so when worn to the legal tread wear limit.
Michelin workshops at Ladoux have shown that a premium tyre, worn to the tread wear limit can perform as well as a brand new lower performing tyre.
With these findings that wet braking distances and lateral wet grip depend on the performance of a tyre and not solely the tread depth, Michelin is calling on industry test bodies, and consumer organisations to start comparing and testing tyres when they are worn to the legal limit; then consumers will start to discover the truth about worn tyres.
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