2.73 to 3.23

[maroonZ]

:help:

Can anyone tell me if factory 3.23 will work with my 2.73 posi unit?

Also, any ideas on the decrease inf uel mileage associated with such a change?

The car is a 2000 Z A4.

[2001NBMZ28]

You mean just the gears? 2.73's have a "2" series carrier, 3.23's have a "3" series carrier, so I don't think they'll work. I put a complete 3.42 rear from an M6 in my car (neither car had TCS), and a TC and only lost a few mpg.

[mrr23]

no. the thickness of the surface where the ring gears fits onto the posi unit is too thick. you will need to get a 3 series carrier for those gears. or get 3.23 gears for your 2 series carrier.

[TwistedSS]

i'd go with more gear! I currently have 2.73's and im putting 3.42's in in the next few weeks. If your worried about gas mileage, with the 2.73's you sit at 2000 rpm at 80 MPH. With 3.23's, its right around 2350 and with 3.42's its going to be around 2500. This is with 245/50/16 tires and .70:1 final drive ratios.

If your worried about top end, with 3.42's and the A4, at the readline you can theoretically reach ~175 MPH

Don't fear the gear!

[98_Formula]

if ur gonna spend the money, do 3.73's... u wont regret it, and the gas mileage between that and 3.23's will not be a big change... but the acceleration will be. I'm going 4.11's in my A4 come summer, if i cant get myself a 12 bolt first... and if i go 12 bolt its still gonna be high gears plus some sticky tires.