I saw a few posts a while back on 3.90 gears that just came out (motive?). Has anyone decided to give these a try in an A4? Want to know what people think about them vs 3.73/4.10's

 

I've heard (pardon the pun) that 3.90's are very noisy in certain rears.

 

They're in a box in my garage . Yes, made by Motive, for a factory 7-5/8" 10-bolt .

I'll be doing the install this winter, so I won't have a report on them until spring .

But as far as how they'll work with an A4, I've had both 3.73's and 4.10's in my car, as an A4, so I think the 3.90's would work just fine . That was initially what I bought these for (I broke the 4.10's on a road course) but then ~2 weeks later and the tranny puked too, so then I did the T56 conversion!

For the 1/4 mile, 3.90's will give you just a little more breathing room up top if you're pushing well over ~110 mph (in top gear ... 3rd for A4, 4th for M6).