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Discussion Starter #1
Hi all, sorry to add to the numerous threads on tyres. I have had a good read through them and then popped into my local dealer, who tends to be very trustworthy, good on price and a local business. They said that I had to fit a Q rated tyre now on EVs and if I wanted something else, they would not be able to 'sign off'. The Michelin energy ev was the only Q rated tyre they could find and this is about £125.

Has anyone else heard about this? He thought that it was something to do with electricity shorting (strange).
 

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2020 Corsa E
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Q is a speed rating so you can fit anything which is a higher rated speed. Ditto load rating. As long as it is the the specified load rating or greater.

I can't believe anyone would think a rubber tyre would be conductive anyway.
 

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Discussion Starter #4
Are they referring to the load rating?
I don't know. But they said they would only be able to fit a q rated tyre. Very strange, but they could only find the Michelin EV at £120 rated at Q.
 

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Discussion Starter #5
Q is a speed rating so you can fit anything which is a higher rated speed. Ditto load rating. As long as it is the the specified load rating or greater.

I can't believe anyone would think a rubber tyre would be conductive anyway.
So for load rating, the original tyres are 91, so it must be higher than this. And the speed rating has to be higher than Q?
 

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Discussion Starter #8
Interesting, I have rang three places and they don't have anything apart from Michelin at this rating and speed. They say it is because of the 91 rating.
 

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Discussion Starter #10
If it were me I'd either get Cross Climates or Primacy 4s anyway.
Is it OK to put two of these on the front if they are summer tyres on the back?
 

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Interesting, I have rang three places and they don't have anything apart from Michelin at this rating and speed. They say it is because of the 91 rating.
Almost all XL tyres are rated 91 - they are more expensive than non XL (usually rated 87 iirc) but plenty of other brands other than Michelin do them

Edit: Q is the lowest speed rating I think, anything above that will be fine, eg (assuming you have 16" wheels) :

 

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No. You'd have to do all 4.
Not true. They have to match on axles but not front to back.

However its strongly advised to put the best tyres on the back, so if you're putting cross climates on, put the existing rears on the front axle and the new tyres on the back
 

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Legally, yes.

Having CC on front and summers on the rear may be a disaster in snow though (less of a prob for Prim4)
 

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Legally, yes.
Legally yes you have to match all 4 or legally yes they only have to match on an axle?

Having CC on front and summers on the rear may be a disaster in snow though (less of a prob for Prim4)
Agreed, hence why I recommended sticking the existing rears on the front and the new ones on the back (which is good practice anyway even if you're replacing like for like)
 

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My last Zoe had different tyres on all four corners. Never noticed an issue with handling.

You’d need to take it on a track to get anywhere near the slip angles required to break traction.
 

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Having tyres with better grip on the front means that the car is much more likely to snap-oversteer in low-grip conditions. With the tyres the other way round, you're more likely to get terminal understeer in the same conditions.

When we used to drive to skiing, we 4 summer tyres fitted and had to use chains on the driven front wheels a couple of times in snow. So it's similar to having the CCs on the front and EVs on the rear. Going round roundabouts at walking pace the rears let go a couple of times, but luckily the car was going so slowly that it wasn't a problem.
 

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Legally yes you have to match all 4 or legally yes they only have to match on an axle?
I see my response was a tad ambiguous! Legally it is ok to fit different tyre brands anywhere on the car as long as they are within manufacturer's spec for that model (with some additional regs for tyres/wheels of non-standard spec)

But putting snow tyres on the front and summers on the rear is disastrous in snow/ice conditions.

Tyre makers advise best tyres on rear axle to reduce oversteer/rear aquaplaning in wet conditions.

This guy makes some excellent tyre videos:

 

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I haven't had any issues putting Michelin cross climates on the car in stages (by axle). The original tyres on the front axle needed to be done just before lockdown and the rear needed to be done a couple of weeks ago. NB Changing tyres like this (summer to cross climate, front axle first) is not recommended. When I say that I had no issues it was actually my wife who was the main driver.

I warned my wife about the risks but she is a careful driver and the weather was good. Only once in extreme wet weather did she notice the difference in grip between front and back and found it easy to compensate for. I would feel differently now heading into winter rather than out of it. I don't know if I would do it again if I was doing it now.

The load rating is the most important thing. It is easy to get tyres that have a higher speed rating than a Q.

I have been told a lot of shit at tyre shops about the tyres. Such as an 87 tyre would be fine (it is what they had in stock) or that H is a lower rating than Q... I now get my tyres from Black Circles and bypass the bad advice (especially since no one has appropriate tyres in stock anyway so there is no incentive not to use an online supplier).
 
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