Different size wheels on a quattro; is it bad?

[G'sS4]

Well I have 19x8.5 wheels on the front & 19x9 on the back of my car. I wanted to go get new tires 235/35/19 for the 19x8.5 on the front & 235/55/19 for the back on the back 19x9 wheels????

I WAS TOLD BY THE TIRE SHOP THAT THE SIZE DIFFERENCE WOULD DO DAMAGE....


Please Help Audi friends......

[Jengel451]

You need to have the same circumference, same as 99.9% of AWD's on the road. So yes, your tire shop is actually saving your differential from destroying itself.

Fronts would be 80"
Rears would be 91.7"

[VMRWheels]

You need to have the same circumference, same as 99.9% of AWD's on the road. So yes, your tire shop is actually saving your differential from destroying itself.

Fronts would be 80"
Rears would be 91.7"

Perhaps the rear tire size typed is a typo? If not then the shop is correct, you would likely incur damage to your AWD system if you were to go with that setup.

Typically, if the outer diameter of the fronts and rears is close enough, it is considered "safe" to run a staggered setup.

[G'sS4]

So then it is ok to run an 19x8.5 on front and a 19x9 on the back with the same size tires all the way around

[pondside36]

You want the diameter of the wheel/tire combo to be as close as possible, with in a few %, can't remember the the exact #. I'm running 19x8.5 (235/35) and 19x9.5 (245/35) IIRC the tire size to achieve this. If you use the same tire size on the back as the rear it will be stretched do to the wider width and will be smaller than the front which you don't want.

[J0HN_R1]

So then it is ok to run an 19x8.5 on front and a 19x9 on the back, with the same size tires all the way around

Yes... Absolutely...

The problems your shop told you about would come from the diameter (not width) of the new tires not being the same.

The front & rears need to be within 3% (diameter) of each other, regardless of width.

But width also needs to be scrutinized somewhat, as too wide of a tire will rub either the fender (during suspension travel) or suspension components (during any rotation).

From all accounts I've read here, a staggered wheel combo for B6/B7 can take up to 245fr/255rr depending on rim width & ET.

But a 235/35fr & 245/35rr set-up might be better, which is within 1.1% diameter of each other...

[G'sS4]

I guess I should just try to get new rims all the way around to save the head ache.

[JEmm]

I guess I should just try to get new rims all the way around to save the head ache.

No reason. Just get 235/35's all around. You'll be fine. The slight stretch on the rear won't change the circumference enough to cause damage, you will be absolutely fine.

[G'sS4]

You think???? I dont want to mess anything up. NO MORE WARRANTY!!!

[pondside36]

8.5-9 is very minimal in the difference, you'll be fine, just go with the recommended tire size above. Lots of people run staggered set-ups with out issue, with even wider rears, with lots of camber and what not. Good luck and post pics.

[J0HN_R1]

I think you'd be happier with the 235/35 & 245/35 combo, and would be totally safe doing so (1.1% difference in diameter)...

235's on a 9" wide rim would have some stretch... 245's would fill the rear out more, and compliment the wider wheel...

[LJH]

but ask yourself this....why would you put a smaller tire on the front of a car that carries 60% of the total vehicle weight?

Cheers,
Jim

[TN82]

so what would be a good tire size for the front if you have 265s on the back?

[wolfs21t]

I used to run 265s on my setup with no problem, 19x8.5\235x35 Front and 19x9.5\265x30 R. I did notice the rear height was lower than the fronts. I recently upgraded the rear to 275x30 and they are almost perfect rolling diameters now.

Here is a pic of the before setup with sport suspension.