295/40/21 tyres.

**donaldscally** · 20-09-2014,04:01 PM

Hi all, this is my first post on an owners forum, so forgive me if I'm going over old ground. I did see one discussion on the topic but wondered if anyone else had fitted 295/40/21 tyres to their Q7 and if they had any issues with it. I have 295/35/21 at present on my 2012 S-Line but wanted the extra comfort and rim protection of the 40 profile.

Cheers

**h2bnd** · 20-09-2014,08:58 PM

Hello I think it was my post on 295 35 21 tyres on here, I've stuck with the original size I have tried pirrellis and yokohamas and am now trying nangkang because the q7 destroys tyres so why spend more, and if they were that bad they wouldn't be able to sell them in the uk.The nangkang as-1 has good rim protection built in and so far are wearing well I think due to the sidewall slightly tapers in. Got mine from love tyres on the net.

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**Jim Walker** · 25-09-2014,07:59 PM

I asked my local tyre supplier about this as we too were considering something like this was informed that it would knock the speedo out but he could not tell me how far out it would be. Still thinking on going down this route but am going to ask a few other people that I know to see what the speedo difference will be.

**h2bnd** · 25-09-2014,08:16 PM

Type in tyre size calculator on Google, this is what I believe alloy wheel suppliers use to work out the difference when fitting larger alloys

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**donaldscally** · 25-09-2014,09:13 PM

I have 275/45/20 standard S-Line wheels with winter tyres which came with 11mm of tread as opposed to 8mm. They have a bigger diameter than the 295/35 but slightly smaller than the 295/40, so you feel it should work but who wants to spend £1200 on tyres to get it wrong. I was thinking of trying to source a part worn to try it. I don't think the speedo would be a big worry as it's only a bit bigger than the 274/45. Still debating it myself.

**h2bnd** · 25-09-2014,09:19 PM

You would have to buy 4 as being 4x4 all wheel tyre diameter need to be the same of from what I understand could cause problems with differentials

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**donaldscally** · 25-09-2014,11:26 PM

I was actually thinking about the possibility of the tyre rubbing on the inner wheel arch after seeing some photos on a Russian website. So I would only put it on a wheel to do a test fit.
I think that size tyre is fitted to the Mercedes GL, their must be one around somewhere.

http://www.audi-club.ru/forum/attach...7&d=1374345319

**donaldscally** · 25-09-2014,11:35 PM

Not much in it from the calculations.uploadfromtaptalk1411684527705.jpg

**AudiQ7fan** · 29-09-2014,09:06 PM

I wonder what the view of your insurance company would be to having different tyres fitted to those recommended by the manufacturer if you were involved in an accident?

If you declare the changed tyre size to your insurer they would probably class this as a modification and hence alter your premium / or decide not to insure.