Mixing different type/brand tyres on car? Is it dangerous or just a myth?

sevenhills

AdrianC wrote: »

If ESP isn't fitted, then mismatched tyres mean that you're going to have different handling left to right. Brake hard in a bend, and that could get interesting quickly.

What do you mean by mismatched?


What if one tyre is a perfectly good 3mm and the other is 7mm?

AdrianC

Yes, that's mismatched - below 3mm is where you start to get into increased aquaplaning risk, due to the reduced ability to clear standing water.

wgl2014

Depending on how much tread is left I would consider just replacing all 4 tyres with a matching set of something half decent. Uniroyal Rainsports are both good and cheap (and suit our rather damp weather).
On the other hand if tyres are relatively new then no issues doing as already suggested.

knightstyle

To pass the French MOT, called CT, you have to have the same tyres on each axle. Not sure why but must be to do with safety.

sevenhills

AdrianC wrote: »

Yes, that's mismatched - below 3mm is where you start to get into increased aquaplaning risk, due to the reduced ability to clear standing water.

You managed to avoid answering my question and instead answered a different one, well done :T

brianposter

Joe_Horner wrote: »

No, the minimum acceptable for insurers is a legal tyre on each corner. They couldn't care less if they're not matched because it won't make any appreciable difference to safety.

Could you provide evidence for this ?
It is very easy to find evidence that different tyres on the same axle are considered unsafe. Whether that is actually true or not is unlikely to be considered by a court, who will simply take the evidence at face value.

AdrianC

sevenhills wrote: »

You managed to avoid answering my question and instead answered a different one, well done :T

You don't think...

AdrianC wrote: »

Yes, that's mismatched - below 3mm is where you start to get into increased aquaplaning risk, due to the reduced ability to clear standing water.

is an answer to...

sevenhills wrote: »

What do you mean by mismatched?

What if one tyre is a perfectly good 3mm and the other is 7mm?

...?

Odd. I'd have thought it a very clear and direct answer to the second of those questions, which also provided a clear answer to the first.

Let me be more explicit in answering the first, then...

I'd consider any pair of tyres that were different brands or non-trivially different models of tyre, or which had markedly different tread depth (especially nearing minimum), or were of markedly different ages to be mismatched.

Happy with that?

sevenhills

AdrianC wrote: »

Yes, that's mismatched - below 3mm is where you start to get into increased aquaplaning risk, due to the reduced ability to clear standing water.

So 3mm to 7mm is a match? You said below 3mm. New tyres are said to be 8mm, would a difference of 4mm be a mismatch?

Car_54

brianposter wrote: »

Could you provide evidence for this ?
It is very easy to find evidence that different tyres on the same axle are considered unsafe. Whether that is actually true or not is unlikely to be considered by a court, who will simply take the evidence at face value.

Taking that evidence at face value, it only proves that the practice is considered unsafe, which is very different from proving that it is unsafe. Any decent lawyer would want hear the evidence from whoever is doing the "considering". And would probably find another expert who considers the exact opposite.

AdrianC

sevenhills wrote: »

So 3mm to 7mm is a match? You said below 3mm. New tyres are said to be 8mm, would a difference of 4mm be a mismatch?

Were "Yes, that's mismatched" and "or which had markedly different tread depth (especially nearing minimum)" not clear enough?