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A4_2.8tuner
02-12-2007, 10:47 PM
i currently have staggered wheels...18x8 and 18x9. I've been running 225/40's on the front and 235/40's on the rear and its been fine...i want to go with more of a stretched look. i wanna run 215's in the front and 225's in the rear, but cant find any 215's with a 40-series profile, only 35...would it be ok to run 215/35 in front and 225/40 in the rear? thanks in advance.

fred2ka4
02-12-2007, 11:27 PM
I wouldn't do it. I am not 100% sure but I have read that on the Quattro setup you need to run the same contact patch at all 4 sides or you risk doing damage to your Quattro. I'm sure someone could elaborate a little more on the subject, but I've just herd that it is bad mechanically for the Quattro

sean1.8t
02-12-2007, 11:36 PM
width won't matter. but you need to keep the final tire diameters with in like 5% of each other

SurferForever
02-12-2007, 11:37 PM
NO NOT AT ALL! ! ! it would be horrible. The different diameter tires would totally screw up your quattro set-up. Infact if one is 225 and one is 235 but they both have a 40 sidewall then they are different tire diameters to begin with and you are currently killing you quattro system. The sidewall number is a percent figure or something of the width. it is directly related to the midth.

Kyle H
02-12-2007, 11:38 PM
The width of the tires doesn't matter to the Quattro system, it's just the outside diameter of the tires.

As long as they're within something like 3-5% of each other, it'll be fine. Try and do a search for some more info, I know this has been talked about a lot.

A4_2.8tuner
02-13-2007, 12:00 AM
yeah i know its been talked about alot, i just couldnt remember what % it had to be within.

i've been running staggered for over 2 years now with no problems FYI, the width has NOTHING to do with it, and why would it? its the rolling diameter that matters.

thanks for the info.

SurferForever
02-13-2007, 12:38 AM
correct, the width doest, but the width is directly related to the sidewall. If your width on one is 225 and the other is 235 but the sidewall is 40 on both of them, then the diameter of the 235 is a little bit bigger then the 225 one

98a4
02-13-2007, 04:25 AM
correct, the width doest, but the width is directly related to the sidewall. If your width on one is 225 and the other is 235 but the sidewall is 40 on both of them, then the diameter of the 235 is a little bit bigger then the 225 one

Your confused. That is true, but add a strech in there. Your 25.4mm in an inch. He has 8" and 9" and the tires are only going to be 10mm = .39" Your thinking if his stech was going to be equal, but it wont be. One will be more stretched than the other, slightly...

Overall Rolling Diameter needs to be within 3-4%, same as it would be if you had low air pressure in one tire.

http://edgeracing.com/tires/2154018/ <--- 215/40/18 6 choices. Expensive because they are rare.

Take strectch out of the equation:
215/40
215 / 25.4 = 8.46 x 40% = 3.385 sidewall height + 18" = 21.385 RD

225/40
225 / 25.4 = 8.858 x 40% = 3.543 sidewall height + 18" = 21.543 RD

Your safe.
/End Thread

Lazer Viking
02-13-2007, 07:59 AM
that calculation is useful..

as much as i hate math, i', glad i didn't have to figure it out

ProOnThaSnow
02-13-2007, 08:35 AM
That equation should almost be stickied somewhere!

98a4
02-13-2007, 08:57 AM
Haha its what a tire calculator does. But its simple math to just do in your head. Hard part is calculating in stretch. Its hard to wrap your head around sometimes.

A4_2.8tuner
02-13-2007, 09:04 AM
so if i do the math then, a 215/35/18 and a 225/40/18 are only about 2.7&#37; apart...which that should be fine to run as well