R22 C8 wheels on C7.5

[ferooo]

Hello,
really want to put wheels from C8 to my C7.5 RS6. I know rim is ok but what about tire? I don't want to use thinner tires on it like C7 needs (285/25/22).
If I put regular C8 size wheel (285/30/22) on my C7, it will be ok ? Ride quality would be the same like on standard RS6 C7 wheels, but what about quattro, can it handle also bigger wheel diameter?
Thanks for help.

[JcatRS6]

Hi mate, I was also looking for a alternative rim for my rs6, does anyone have a picture of the c8 rs6 wheel on a c7 as I can’t find one anywhere.
Thanks

[morski]

Has been done for a member on here.. search some older threads

[ferooo]

Has been done, on red RS6, C8 R22 wheels but tires was 295/25.
I am interested in 285/30/22 on C7.5 RS6 (if quatro will be ok with this tires). That's the question

[Holt2498]

30 profile tyres will definitely cause issues, expensive mistake if you are buying these tyres new.

Although you may think there’s hardly any difference from a 30 profile to a 25 profile, this is certainly NOT the case.

Hope this helps.

Original link below for the thread.
viewtopic.php?f=76&t=141515&p=957929#p957929

[ferooo]

What kind of issues you mean? fitment, quatro, police, insurance..?

I've ran 275/35/21 on A7 4G (what is basically the same like A6) without any issues at all (no other modifications to ET or suspension).

Overal diameter of 275/35/21 is 726mm and 285/30/22 is 730mm (only 6mm difference). Just for sure I will try those 275/35/21 fit on my RS6 (I sold my old A7 to my friend).

[Holt2498]

You’ll get catching and rubbing issues on the arches front and rear and also catching with turning circle issues.

“I've ran 275/35/21 on A7 4G (what is basically the same like A6) without any issues at all (no other modifications to ET or suspension)”

a lot of what you say here completely depends on the offset difference, the diameter and width of the alloys - the C8 RS6 22” alloys are bloody massive and here lies the problem with larger profile tyres as the C8 is quite simply designed to accommodate larger wheels than the C7.

Hope all the above makes sense, however the simple solution to satisfy your mind is to try a test fit C8 RS6 22” alloy with the tyre size of your preference and see for yourself.

[ferooo]

I don't mean my posts like I dont believe you about fitment issues I am just working with numbers here

Do you know what is inner clearance between tire and upper arm in your case?
Inner clearance between rim and upper arm you put in your thread:

By this foto it looks like there is enough space for 11mm taller tire (295/25 vs 285/30).


Compare RS6 wheels to my old A7 wheel setup:
RS6 - 10.5x22 ET19, 295/25/22
A7 - 9x21 ET35, 275/35/21

By this comparison RS6 wheels will be 3mm closer to the upper arm and wheel radius is 2mm bigger.

[Holt2498]

The upper arm is not the problem here, it’s the width of the alloy as it pushes the outer edge of the rim to the very limits of both front and rear arches, 30 profile tyres in my opinion will cause the issues as the arch gap is very minimal, maybe on a standstill it will look ok, but once they’re on the road you’ll get lots of bottoming out on the rears and scrapes on the front when cornering hard and I am very confident it will catch on the inner arches on tight turning.

Hence why in my thread I tested the 20” alloys with the 35 profile tyres and spaces to give me a similar effect of the 22” alloys, then for every inch you creep up in ally’s you take away 5 profile, hence the 295/25/22 tyres.

After my own research and then pulling the trigger on purchasing I feel this is my best feedback

[KianFoster]

While I'm not an expert on wheels and tires, it's important to consider a few factors before making the switch. The tire size you choose can affect your speedometer accuracy and may also impact your car's performance, so choosing a size that is compatible with your car's specifications is important. It's also worth considering whether your quattro system can handle a larger wheel diameter, as this can affect your car's handling and stability. I would recommend consulting with a trusted mechanic or wheel specialist and also considering high-quality options like COR Wheels to ensure you get the best possible fit and performance for your car. Good luck with your decision!

[NME]

I ran these on mine for a while and generally had no issues.

I had the CETE air lowering module as well, and could run it quite low.

The only issues I had were if you booted it ( I had MRC 750 BHP), it could cause the back arch to catch very slightly.

Nothing major. And you got the tiniest bit of rubbing on full lock if going over uneven ground whilst doing it.

They looked awesome and it was worth it!