OK to go from 20" to 18" ?
 

Hi there!

Planning to replace OEM 285/45/20 GY RF with 295/45/20. I got good mileage on the GY RF (38k mi and still going for another 10k) no compaints about mileage of course but, they are noisy and have poor traction (scary on snow). No need for a dedicated set of snow tires where i live though.

The 295 are non-RF and i know that we have the air compressor, tire sealant and audi care :). buy anyways, I would like to ask for your opinion on having a spare wheel\tire using the following (cheapest option):

Tire
https://www.tirerack.com/tires/tires...omCompare1=yes

Wheel
https://www.tirerack.com/wheels/Whee...dClar=Prestige

Comparison vs 295\45\20:
https://tiresize.com/comparison/

Just an FYI: As it was discussed elsewhere, 295s are too wide for the stock rims and (unless you'll be getting them with new wider rims) you'll be pushing your tires safety limits posted by their manufacturer. I am not saying they won't work though...

The only difference between 295/45 r20 and 285/45 r20 is the 4% larger sidewall and 3.6% greater width. With these number, I don't see how the 195/45 r20 tires cannot be used on stock 20" rims safely.

You and I can see and or not see all we want, but if you will check manufacturer specs for two tires you'll find that 285s can be installed on 9" wide rims (20" Q7 OEM) while 295s cannot be requiring at least 9.5" wide rims. Here is the link to one of the very nice tire choices that I would wish I could install on my Q7, but will not be for an aforementioned reason:
https://www.continentaltire.com/prod...5-zr-20-114w/?
Approved rim width is 9.5"- 11.0".

These were the tires I was considering as well to replace the GY RFTs

You make a valid point, but 0.5" is a very small difference. Specs or no, I would like to know if anyone else is currently running 295/45 r20 on stock 20" rims and what their experience is.

I don't think a reputable tire installer will do the work as it will make them liable for any possible negative consequences of the tire's spec violation. My local Discount Tire's guys said flat NO to it and so did the dealer.

Not true. I debunked that theory.
295 is more than safe on a 9" wheel and any reputable shop will install it.
I had a dealership and Discount tire do mine and had 3 different models of 295/45/20's mounted.

I went with 275/40/20 conti DWS06 and they are phenominal. if you want to stick with factory size runflats (or other size runflats) enjoy limited selection, more unsprung weight, louder ride noise, and less compliant ride. I understand the runflat portion of things is comforting, but not worth it IMHO.

I think I like your version better :)

Dude, there is no theory to debunk! :) The truth is that spec has numbers posted and that is it. We can choose to install whatever you or I want against posted limits and find a tire place willing to oblige no matter what. Then we can make our own beliefs about "more than safe" operation and be possibly quite safe for an entire life of the selected tires...But Continental DWS 6 are also made in size 275/45R20.