16" rims: barring 215/55-16 would 225/50R16 or 205/55R16 work better?

You shouldn't have to worry about pot-hole damage with 17 inch wheels. Size 18 and 19 inch, probably, but not 17. Best bet is to go to a tire store and ask them what wheel/tire combo will fit your car. I put 19 inch BBSs on my RS6 and damaged a wheel on pot hole on an interestate. I tried to have it repaired but the wheel repair shop wouldn't touch it because of a crack. So, I had to buy another one (and a new tire). d;o(

Dave

I've seen places about 4000-4500 miles out east where the area covered with alphalt is about %25 of the "paved" roadway. It looks more like swiss cheese with 75% of the total area occupied by giant potholes and it would've been much better if it was just gravel. So trust me, I'm not talking about a US grade roads here but some local rally-worthy roadways: at times I was moving at about 30mph and that was only due to a heavy duty suspension and tires with 70 sidewall. The rest of the traffic was crawling to the tune of 10mph or so. I had a sidewall blowout as a result of such a "spirited driving" in that section and one of the tires looks like a motorcycle tire now. It's anything but flat :)

I would rather not subject [fragile] A4 front suspension to a test like that but that's a scenario I do not want to exclude entirely. So I would not go past 50 and I think 17" are calling for 235/45-17 which are making me a bit nervous.

Don't get me wrong: I LOVE sport suspension and the associated short sidewalls, but in the context of the local roads and doubts in A4 suspension longevity I have to pass on both.

Does audi have any limits on difference in wear between all four tires like subaru does or you can pretty much replace them just on one axle or, as in your case just a single tire?

I assume here that your RS6 have some form of a torsen center diff.

An aspect ratio of 45 should not affect normal driving on *normal* roads. How often does the original poster plan on driving on

*moonscape* New England roads? It stands to reason that if such a road as you describe is encountered that you would lower your speed *regardless* the aspect ratio. I have 100k miles on my RS6 with a majority of it on Massachusetts/NH/ME roads. And I have been on a road you described cursing all the time, but driving very carefully. My wife and I rallied for several years in VT/NH/ME/CT/MA with cars that included a Porsche 944, VW Quantum, and several Audis including the first iteration of the S4. I had only one problem with a wheel/tire and that happened when I went *off* the road and hit a stone destroying the wheel of the Quantum.

It depends on the wear. I had just put on 4 new Dunflops, so replacing one tire was not a problem. However, in the past when the tires were worn, I replaced all four if I had a flat. Best to check with your Audi/tire dealer

Dave

On Wed, 23 Mar 2011 09:46:01 -0700 (PDT), against all advice, something compelled Anton Success , to say:

Yes. And the tolerances are tight.

Noted. A4 1.8T avant with reputably evenly worn tires is > An aspect ratio of 45 should not affect normal driving on *normal*

Daily. It's like that in the parking lot of the newly built pigeon hole style apartment building I'm renting.

Well, I was driving an rwd antique beater (fiat 124 knockoff) with 70 aspect ratio tires: I felt entitled to drive at 2x the speed of the the people who were concerned about the well being of their suspension, tires and cars in general.

I've paid the price a in a form of a sidewall blowout that I've discovered upon venturing to the car in the morning: apparently it was sitting with that flat overnight while I was recuperating at the motel. The SOB at the tire shop did not bother to patch up the tire before installing a camera. Subsequently last weekend I was faced with a blown camera, a larger sidewall cut on a tire with TONS of tread left rendering the tire AND the inner tube unusable. So the tire lasted a year after the incident instead until the tread was worn out.

Good help is hard to find.