Tire question? Sizing

[dutch]

My question: Do I need higher sidewalls? My understanding is that sidewalls help absorb flex from turns, bumps, etc.

I am running Toyo Proxies 255/30 R19 on my 2001 Audi 4.2. I noticed a high speed wobble last week and brought it into my fav place. They said the right front is splitting and pointed wire sticking out. These tires have about 15K miles on them and I am no track racer (tons of freeway miles). I have coilovers so I can raise if necessary.

If I am looking to put on 35s, do I need to replace all four or just two?

TIA

[PhätTony]

I dont know much about that, but I do know that those tires a extremely low pro for that weight of car. I'd never go below 40, but many here that I know have 35's. IMO
Not to mention bad gas milage

[bugzy]

255/30/19 are the proper tire size to keep stock rolling diameter on the A6 4.2L

I think going to 265/30/19 would be more ideal then going to 255/35/19

the 35 series would increase the sidewall more than necessary and might cause rubbing

where as the 265/30/19 would only be a small increment larger in width and diameter, and would induce higher chance of rubbage than the 255's but not too much

according to most talk about quattro, its recommended to replace all 4 tires at once, unless 2 tires are no more than approx 25% wear difference, so if your at 75% wear, i think you'll be fine, but if your 2 tires are 50% or lower, would be idea to replace all 4 at once

would also be good to see if you got a camber issue, is the tire wear showing on the inside of tire or center of tire?

[PhätTony]

the question is what are the specs of the wheel wells on this car? I had 245's on a car before with insufficient wheel well depth and it shredded the tire like cheese from the lip. Still drivable but made the tires look bad. I'd find out first what the diameter of the well is first. Also look into turn radius.

[bugzy]

Keep in mind he's got an A6 4.2L

the car stock runs 255/40/17's, so going to 255/30/19

[dutch]

Thx for the reponse Lon. I posted this before we IMed. I am thinking about going with a different brand? i can take some pics tonight but u can see there is a lot of tread left. Just bummed that this is the 2nd one I have had to replace...each time buying a pair. I could open a used tire store from my garage ;)

[bittebb]

How much offset do your wheels have?

I agree with Lon on the tire sizing. You have to remember that the sidewall is based on a proportion of what the width of the tire is, but if you're running too much offset on the wheels it might not make a difference what tires you run - they still might rub.