How reliable are the ratings on tyre info labels..?
Discussion
Without wanting to get into the whole 'cheap tyres will kill you' debacle; how trustworthy are the A-E ratings? I'm thinking specifically of the 'wet weather grip' one.
Reason being; I'm tyre shopping at the moment and often user reviews of a tyre seem to totally go against the labels. For instance, I am looking at a tyre from Brand X which has a 'B' rating for wet grip. However, many user reviews imply said tyres are not all that good in the wet, whereas a similarly priced model from Brand Y has a wet grip score of C but seems to rate more favourably with users. I wonder how much is down to the other brand having a more snazzy tread pattern and a slightly more aggressive name?
Reason being; I'm tyre shopping at the moment and often user reviews of a tyre seem to totally go against the labels. For instance, I am looking at a tyre from Brand X which has a 'B' rating for wet grip. However, many user reviews imply said tyres are not all that good in the wet, whereas a similarly priced model from Brand Y has a wet grip score of C but seems to rate more favourably with users. I wonder how much is down to the other brand having a more snazzy tread pattern and a slightly more aggressive name?
Rarely do manufacturers' or trade bodies' testing exactly mirror the findings of users. I was at the Transport Research Laboratory when two tyres were demonstrated on identical cars. The reduced rolling resistance of one against the other was shown by pushing both cars down a slope to see how far they would roll. The car with the new 'eco tyre' rolled significantly further but would that be noticed by end users? I doubt it.
vsonix said:
in other words, it's a load of crap and I should take it with a handful of salt...
Errr, no, and your point that they don't all carry 'A' ratings kicks that cynical idea straight out of the window. Yes it is true that the manufacturers have to fund the testing themselves (because governing bodies are not in the habit of subsidising private enterprises) meaning that a lot of manufacturers will end up doing the tests themselves (or more likely as the system gets up and running they will contract it to an organisation set up specifically to do it), but they have to be able to prove that the tests were done to the relevant ECE standards and this not being the case the products can be banned from sale instantly.OK, so no system is perfect, but you can be sure that rival manufacturers will be putting competitors' tyres through the tests and be ready to whistleblow if they find anything demonstrably wrong with the ratings.
BritishRacinGrin said:
The 'wet grip' rating doesn't measure wet grip. It measures stopping distances on a controlled surface with a fixed water depth. In other words, it's a limited and specific test which, while objective, doesn't give you the slightest idea how the tyre will perform in the real world.
There are none so blind as those who do not want to see. It will tell you exactly how the tyre behaves relatively to every other in that test, which is a real world, straight line stopping test. It does not measure every scenario but it is a valid result.
Some people are finding it very hard to believe that their expensive tyres can possibly be worse than cheaper ones at something important and safety related. People will want to argue black is grey because an objective test does not agree with their subjective opinions, but the tests are valid and meaningful.
r11co said:
It will tell you exactly how the tyre behaves relatively to every other in that test, which is a real world, straight line stopping test. It does not measure every scenario but it is a valid result.
It's a valid result for that specific test. And, yes, it's purely a comparative. Just the same as the official fuel economy figures are a comparative, and perfectly valid for that specific test - and similarly representative of the real world, with some coming quite close and others being miles out...Plenty of magasines do group tests of tyres, which do objective back-to-back testing of different models.
I guess the tyre labels are a bit like the NDEC fuel economy test or NCAP crash tests - useful until manufacturers start tailoring their products directly to the test rather than to what the test is meant to be an example of.
I guess the tyre labels are a bit like the NDEC fuel economy test or NCAP crash tests - useful until manufacturers start tailoring their products directly to the test rather than to what the test is meant to be an example of.
Edited by kambites on Sunday 18th May 15:42
r11co said:
BritishRacinGrin said:
The 'wet grip' rating doesn't measure wet grip. It measures stopping distances on a controlled surface with a fixed water depth. In other words, it's a limited and specific test which, while objective, doesn't give you the slightest idea how the tyre will perform in the real world.
There are none so blind as those who do not want to see. It will tell you exactly how the tyre behaves relatively to every other in that test, which is a real world, straight line stopping test. It does not measure every scenario but it is a valid result.
Some people are finding it very hard to believe that their expensive tyres can possibly be worse than cheaper ones at something important and safety related. People will want to argue black is grey because an objective test does not agree with their subjective opinions, but the tests are valid and meaningful.
I recall Evo (I think it was) doing a tyre comparison test years ago.
To test dry stopping distances they disconnected the rear brakes on a non ABS equipped car then locked up the wheels from a set speed.
I remember thinking how useful this info was, should I ever forget to drive properly, disconnect the ABS and remove the rear brakes from my car!
To test dry stopping distances they disconnected the rear brakes on a non ABS equipped car then locked up the wheels from a set speed.
I remember thinking how useful this info was, should I ever forget to drive properly, disconnect the ABS and remove the rear brakes from my car!
Ari said:
To test dry stopping distances they disconnected the rear brakes on a non ABS equipped car then locked up the wheels from a set speed.
I remember thinking how useful this info was, should I ever forget to drive properly, disconnect the ABS and remove the rear brakes from my car!
I was thinking more laterally than stopping distances! I remember thinking how useful this info was, should I ever forget to drive properly, disconnect the ABS and remove the rear brakes from my car!
... tyre life (on a relative basis) is also a pretty major omission (and could be done using a standardised loading/turn cycle).
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