Capt William

I think the main reason for this movement towards lower profile tires is the same as the "jacking up" of the rear of cars in the 70s. It is the cool new look. I had 17" on both my 2.7ts and they were no problem as long as I kept the tire pressures up (about 40 psi). I am just going to 18" wheels primarally because I want to go to some really big rotors. I do like the handling with the 18" tires a bit better but some of the difference is that the 18s are wider and a different tire. You will get a bit less roll with lower profile tire because they will deflect less under load. You will also get quicker responce to steering inputs for the same reason. 18"s will be a bit more likely to bend on potholes, 19" would be nearly impossible if you stayed with the stock tire diameter, 20"s would bend going over gravel at high speed (I am exaggerating but I don't know how you could live with them).

Egil A64.2s - S6

The main difference between the 16 and 17" is looks and a small change in ride quality. With the 17" you get, it is personal, a better look, crisper handeling feel but a slightly harsher ride. It will come down to a personal decision. Go the Lexus route for comfort with the 16" or the S series route for handeling with the 17".

My Audi in my sig had 17"

quattro27t

Been riding on my 18" rims with 235/40-18 with no problems -even over potholes and such. Only downside is the costs of tires, but you can get the KUMHO 18" tires for around $100/each. You love the looks and handling. Do a search this forum and you find out that many can't not stand the wimping 16" stock - way too small for a performance sedan.

Ming rings in Minn

The A6 is mainly my "family" car. My other car is a TT, that has 16's for winter and 18's for summer and I love the 18's, on a TT.

CT_A6_guy

It came with 17"s but the tires were just about shot (still within Audi Certification though - not sure if that says a whole lot). So I picked up 4 16" wheels with Pirelli SnowSports at Tire Rack (about $1,000) and have been using them this winter. There is a HUGE difference between the Pirelli's and the Dunlops in the snow we have had here in Connecticut. Come spring, I will get 3 new Dunlop 9000s (spare is ok, looks like it was on the car, but only briefly) for the 17s and I will be good to go.

beep-beep

255/xx/16 handle as good as 255/xx/19. You just think, that 19" handle better, because they do not slide in the corner until last moment.

on top of it 255/xx/16 are lighter and more reliable than 255/xx/19.

Just look at any race car (I think Panoz uses 45 or 50 aspect).

JayGon

Me, too. I put the stock 16" wheels with 225-55-16 Winter M2's and polished 17" Sport w/255-40-17. Thought about using the 17" pie plates for winter, but sold them and went with the smaller size.

18's look great, but I think a suspension upgrade is advised when doing a Plus 2 (from 16") upgrade to close the fender gap.

Jay

6sidua

it don't mean a thing if it ain't got big bling!

but you're right about everything else and lots of racing venues go with 45/50 or even higher aspect ratios....

it just a phase and will pass eventualy.

i read that jay leno had some custom billet wheels made in 17s but they're visually masked to look like 15s... so maybe the movement has started.
cheers

Ming rings in Minn

like go from 215/55/16 to something like 255/50/16,,, would I get more performance/ride comfort for the $ with 255/50/16 or should I spend the cash on 17in rims.

6sidua

wider usually means louder and with more steering feedback, but this goes both ways...quicker turnin but more shake in the wheel as the wider/lower profile wires find the road.

lots of other pro/con issues have been discussed here, so search a little. it might be wiser to only go to 225/235 is you want to balance "performance, cost and ride comfort"
cheers