I didnt check older posts but I was wondering if you can run wider tires in the rear on an awd car or does it affect the handling of the car? I know on alot of rwd cars you can but an awd? Thanks.

 

It's tricky... because you have to maintain the same overall diameter of the tire... because all wheels have to spin at the same speed...

That is how quattro works... it is a mechanical system that keeps all wheels spinning at the same speed.
Sooo if your front tires had a smaller diameter (and resulting smaller circumferance) then they would spin faster than the rears... Quattro would be like "uh oh, the front tires are slipping -- lets send power up front!"

Then your differential explodes from heat... good times. Haha I might be being a tad bit dramatic... but it would be bad, that's for sure.

 

He's talking about wider tires. Not larger.

I've seen a couple A4s with wider rear tires.

 

It can work, though I believe it encourages understeer slightly. You could counteract that with sway bars, I think.

 

Headshok is talking about wider I believe….. because as the tires get wider even though the height may still be something like a 45 series that number is in proportion to the width so its over all diameter will be different and that’s what screws with $hit. All you gotta do is make sure the diameter is the same and that can be really hard to do..

 

Yeah that is correct badluck...

Like, a 235/40/18 up front might have to be mated witha 265/35/18 in the rear... as you go wider, the tire also gets taller, regardless of the height profile... because that # (35, or 30) is a RATIO of the width (235 or 265 in this case). So, using a wider tire, 265 for example, might require a 30 series in the rear.

You can check tirerack specs... they give you the tire diameters in the "specs" of any given tire.
Example:
http://www.tirerack.com/tires/Spec.j...Eagle+F1+GS-D3

Note, 235/40/18 has an overal diameter of 25.4" -- to match that, you would indeed need to use 265/35/18 -- overall diameter 25.3" (close enough)

BUT if you were to use even a 255/40/18 (they don't have a 265/40/18 to compare) overall diameter shoots up to 26"... which is .6" more than the 235/40/18 you'd have up front... and a 255 isn't a whole lot wider than a 235...

Also: tirerack specs also have a "revs per mile column" ... which is cool.... matching a 235/40/18 with a 265/35/18 would mean 822 revs per mile up front, and 825 revs per mile in the rear... like I said, close enough. the 255/40/18 is like 803 revs per mile.

 

http://www.1010tires.com/TireSizeCal...?action=submit

this site came in handle to figure out the tire sizes...

 

yep u got got is figured out basically. Wider tires in rear encourage understeer; roller diamterer must be the same; 235 tires on a 8.5" wheel will be higher than 235 tires stretched over a 9" wheel, etc