All-season tyre speed ratings - same rule as per winters?
All-season tyre speed ratings - same rule as per winters?
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Discussion

a11y_m

Original Poster:

1,861 posts

252 months

Tuesday 5th March 2019
quotequote all
I'm aware that it's permissible/common practice to use winter tyres with a speed rating less than a vehicle's top speed, e.g. https://www.michelin.co.uk/winter/load-and-speed-r...

But, does the same apply for all-season tyres?

Reason I ask is I'm looking for all-seasons to use on my car over the winter months (winters vs all-seasons is a different discussion not for here!). A particular model I'm considering due to good review - the Nokian Weatherproof - is only available with a V speed rating, whereas my car requires a minimum or W or Y rating (top speed around 170mph on my Monaro).

My understanding is with winter tyres you're unlikely to trouble the top end in wintry conditions, hence the rule. However all-seasons can be used all year round (although that's not my plan) so could be fitted in the middle of summer and so could be fitted in conditions which allow the top speed to be troubled.

All useful advice appreciated.
Thanks.

Pica-Pica

16,603 posts

114 months

Tuesday 5th March 2019
quotequote all
My understanding is that summer and all-season tyres should match the summer speed rating. The speed rating is related to speed AND acceleration.

ging84

9,548 posts

176 months

Tuesday 5th March 2019
quotequote all
There is no issue with speed rating on tyres in UK
For the mot as long as they are above K they are fine, you can get an advisory if they are lower than recommended, but there is no reference guide, so unless you are at a main dealer or a tyre supplier they are unlikely to have the information to even check.

a11y_m

Original Poster:

1,861 posts

252 months

Tuesday 5th March 2019
quotequote all
I didn't realise I could get Michelin CrossClimate+ in Y speed rating, so that removes any doubt I'd have going for something with a lower rating if I decide on all-seasons.

300bhp/ton

41,030 posts

220 months

Tuesday 5th March 2019
quotequote all
Pica-Pica said:
My understanding is that summer and all-season tyres should match the summer speed rating. The speed rating is related to speed AND acceleration.
Can you show me how they are rated for acceleration?

ging84

9,548 posts

176 months

Tuesday 5th March 2019
quotequote all
300bhp/ton said:
Pica-Pica said:
My understanding is that summer and all-season tyres should match the summer speed rating. The speed rating is related to speed AND acceleration.
Can you show me how they are rated for acceleration?
They drop them from a tall building, a good tyre will accelerate at about 9.8 m / s2
A bad one also about 9.8, its a pointless test but the EU forces us to do it.