moving my '92 S4 to 17x7.5 ET35 rims for the warm season. My tire guys tell me the widest recommended for the car is a 225/45ZR tire. Anyone have experience with this or wider sizes on a similar size rim or an opinion on the following tires?

Probably will go with Pilot Sport A/S. Other considerations are Toyo T1/S or Potenza SO3.

Don't quote me on this, but I' pretty sure you can run 235's on those wheels. To be safe, take them to a shop and see what can be done...the only downside is that you might have a greater chance for blowout as you're taking that wheel to its limits. I'm running the S03 PP's right now and let me tell you, I love em! It may also help that I'm running 255's...Yeah, that may have something to do with it...

I am pretty sure that a 235 width tire is the widest application for a 7.5 inch width rim. I have 235/45-17s on my S6 and it looks great although my wheels are 17x8. As to tire choice, because the ride quality of the S6/S4 is stiff over small imperfections in road surface, I would not choose a SO3 or T-1S tire for your application. I really like the Toyos and have them on my 2000 S4 which has a more forgiving suspension. But on the S6, I went from RE730s to Dunlop SP9000s and find the grip/ride balance to be just right. THe other tire I would consider would be the Pirelli PZero Rosso.

How are the 255's with road camber? Do you find that they like to wonder around on the uneven pavement?

Yeah, the 255's pretty much go where they want, but it kind of helps that I undid the overboosted steering at low speed. It really gives a lot more feel. They do wander a bit, but they do handle better, regardless, as long as you have strong arms. :-)

-Joe
1994 UrS4
TAP Stage I
Big Reds
Samco hoses
Bailey Motorsports BPV
RS2 17x9's w/255/40/YR17 S03's