Totmacher

I recently bought a pre-owned Audi assured 2.8QA. I just noticed today that the front and rear tires are different. The front are Good-Year F1 GS 205/55ZR16. The rear tires are Good-Year GS-C 225/50ZR16. I read in the Audi manual that the tires should match on a quattro, how true is that statement, the tire treads look similiar. I also noticed that the rear rims don't have weights on them like the fronts. I don't know much about tires, what should I do? <p>

Nidal

Take it in to the dealer and ask them, or you can try the wheel forum on A4.org

stanj

Different sizes tires front and back, that's not good. At least the wider ones are in the back. Your car should have 4 tires with the same width. <p>As for the weights: it is possible to balance a wheel without visible weights, if they are placed at the inside of the rim at two different distances from the edge. I had that done to my SO2s until my dealer re-balanced them... now I have weights again.<p>- Stan<br>

ChuckH

I don't feel like trying to figure out the calcualtions, but those two sizes will have different rolling diameters. bu how much, I don't know. It's not good to have a significant difference between front and rear. <p>The biggest problem I see here is that the wider tires are ont he rear. Since I don't know how the tires compare as far as traction goes, I'm just going to go ahead and assume that those two types of tires would have the same traction if they were the same size. Since the rears are 20mm wider, you will essentially have more traction at the rear (due to extra contact patch). Since the A4 is already designed with some understeer (front end to break loose before rear), the last thing you want is to have more traction at the rear. This will just make the understeer more pronounced. Scary! <p>It is true that the weights can be placed on the backside of the wheel, and that is the best way to do it. If you are not having vibrations while driving, they are probably properly balanced. <p>Without question, I would not drive that car with the different types and sizes of tires front and rear. As far as I'm concerned, this could have an adverse affect on the handling of your car. You may not feel it in normal driving, but in the event of an emergency or something, the car may not respond as intended. <p>As a side note, if this is an Audi Assured car, I would think that the dealership and or Audi are responsible for selling you a car that is at factory specifications, or at a very minimum, one that has matching tires. If I were you, I'd go to the dealership and tell them that you are concerned about adverse handling and possible longterm damage to the car as a result of the different tires. I'm sure they will take care of this issue for you, unless they want to be held responsible for anything that could result from this. Good luck!<p>Charles<br>

ChuckH

...having a wider tire on the rear of an A4 is asking for trouble. Since the car is built with understeer already, having less traction in front than in the rear is not safe in my opinion. THe only time I have ever seen different tire sizes on a quattro was when the wider ones were int he front to combat understeer, and even then, the car was a track use car, and there was no concern for driveline components or anything. All that being said, I think you were aware of this, but it just slipped your mind. And, I'm here to remind you! :-) :-)<p>Charles<br>

stanj

Silly me, of course! It's too late /early :-)

stanj

SAME rolling diameter (did the math)

Totmacher

nt<br>

stanj

There is the still valid point made by Chuck: having two wheels bigger than the others, esp. the rear ones on an understeering car, is not optimal. I mean you can't damage anything with it, but your handling will be severe understeer. That by itself isn't "bad", other than undesired.<p>- Stan<br>

Steve S.

I would get two of whatever tire you think is best...and have four of exactly the same tire, in the same size, on the car. Different tires have different handling characteristics, so your car may exhibit weird feelings when going through turns. This is especially important in a Quattro. If it was my car, I would actually buy FOUR new tires that I was familiar with. Those tires you mentioned...I have never heard of anyone with an A4 with those exact tires. AND, I have been on this forum for over 2 years.<p>Steve S.<br>97 2.8QM