Tire Rubbing

[HollandRS6]

Hi -

Thanks for the earlier welcome on another thread as I am a new member. I just changed out the Dunlop winter tires that came with the car (225X40 R18) for Bridgestone Potenzas (255X40 R18) and have light rubbing sounds when the shocks dip deeply. I read through some of the earlier threads, discussing wheels and offsets, and also saw that there are separate winter wheels with 7.5 inch width. Is the problem likely that the winter wheel offset is different than the 'Summer' wheel, and that this is causing the rubbing? Anyone else have this issue before, and should I feel an idiot for not knowing when you move to this level of auto you should be expected to fork out for two sets of nearly identical rims?

Thanks, Chris

[Lateknight]

What is the ET (offset) of your wheels?
It should be cast into the wheel somewhere - either around the central hub or if your unlucky it might be on the back of one of the spokes (wheel off job).

Are your 18" wheels Audi or aftermarket?

Your winter tyres are an odd size (not that it matters in this case). I would have expected 225/45r18 to be an RS6 winter size not 225/40r18. That makes your summer/normal tyres taller aswell as wider than your winter tyres.
The 255/40r18 summer tyre size is correct for standard 18" shod RS6 though.

See if you can find the offending wheel that is rubbing. Check the tyre sidewall/edges (inside and out) or look at the liner trims underneath the wheelarches with a torch for scuffing.