max rev

I am trading in my '04s4 for a 4.2 allroad because I need an offroad vehicle and I really want to stay with audi. Anyway, the low profile tires are not going to cut it but I would like to stay with the 18" wheels that come on it. My question is: can I fit 255/55/18s that would increase the overall diameter of the wheel tire by 2.36 inches. Thanks

mowog

so at 70mph on speedo your doing really 76-77. I would question them fitting without rubbing something. How about a higher profile with narrower tread ? Your only 10 mm wider so that could be ok but you would probably have to stay at level 3 (maybe 2) for tire clearance. I wouldn't spend any money on this until I heard from someone who has tried it. Why not buy something for half the price that you don't mind beating up? What kind of offroading do you need to do?

LCP

That really seems like a lot. Maybe try 255/50-18's or 245/50-18's instead.

HPH

...but all may not be lost.

Originally, Audi sold as an allroad option sets of 16" winter wheels. Unless the brakes have grown since 2001 (and others here will know this), you can find a set of those wheels and put some sturdy tires on them <i>to use when you go off road</i>. Then you can take advantage of the 245/45-18 high-perf handling when you're not off road.

Options, all within 1% of the stock size (which will preserve gear ratios) are 225/60, 215/65, and 205/65. Note that going taller on the 18" wheels will raise effective gear ratios, not something you really want off road. HPH

ColoQuattro

Michellin makes a Pilot in a 18" as well as a Cross Terrain in a 18" size. You are however talking about a BIG, HEAVY tire and wheel. I had 275 mm Pilots then later the Cross Terrains on my '01 Grand Cherokee which did have large wheel wells intended for upsizing and no intruding control arms and suspension peices. Clearance was a problem for it with these tires without a lift.
Right now P245-45-R18s on my AR leave only aobut 3/8" clearance between the control arm and the tire. Plus the tire sets pretty far out into the wheel well flairs. IMHO you will have clearance problems not only with suspension parts but at full turn lock as well when the car is in its lowest suspension setting just sitting still. Add in suspension travel at lock and I will bet $$$ that you will rub.
A 2"+ increase in diameter is a huge increase....if you need that much tire sidewall for rocks and shock absorbtion I would suggest going to a smaller dia wheel like a 17" max, 16" preferred. And if the offroading gets rougher than that I would pick another vehicle with a low range transfer case. Additionally getting that extra sidewall height will negate any crisp handling characteristics of an 18" tire.
Just my opinion...and I could be wrong....but I had several Jeep GC's and fitted alot of tires on them for offroading over the past several years.
My '01 Jeep GC could never compare to my allroad on the pavement, but my allroad could never compare to my '01 Jeep GC off road.

max rev

mostly just fire breaks and dirt roads with ruts and such, so nothing totally extreme. I just know how pathetic my '04 S4 is at even minor pot holes and since it has the same tires I shudder to think that the allroad probably shouldn't go off road at all with that 245/45 tire. The reason I picked the 255/55 is they are standard on the cayanne and a good street tire as well but only available in certain, larger sizes.

max rev

would you feel comfortable driving fire breaks with those tires?

ch7656

If a trade-in I'm curious what type of money they're offering.

TIA

max rev

I traded in my old s4 and I was almost about to buy the 4.2 allroad, but after I drove the new S4 I couldn't resist. Obviously in hindsight I should have bought the allraod right away, but I did really enjoy the S4.

ColoQuattro

The Michellin Cross Terrains were a great all around tire. Not a total performance tire but not really a total offroad tire either. Good in the snow and for light offroading they were a perfect compromise. They were load rated for the Jeep which tipped the scales wet with my fat butt inside at 5300 LBS. The Pilots were more pricey, better on pavement but offered less mileage wear. I was very comfortable with those tires.