In Reply to: 94 540i Differential posted by John Gimpl on November 21, 2000 at 12:57:25:
My highway mileage is exceptionally nice 23.5 @ 85mph. Around town with my foot in the throttle is around 16.5 or so. FYI, I also have the Dinan air tube and tranny chip and Conforti engine chip which combined, makes the car feel like a real muscle car. Anyway, if you get the diff from Korman, it is remanufactured and it will set you back $1600 and Dinan is priced the same. Vines has them for $495 or so - They're usually out of a 750 or 850. Jack knows his bimmers and will help you with whatever you need.
Diffs are commonly thought of as a poor mans supercharger - it's definately a step in the right direction and it just bolts right in - the pickup for the speedo is on the back of the differential and is already calibrated to your speedo in the car. 2-3 hour job.
Can anyone tell me how much of an effect a new diff has had in their car and which one they put in? I have been considering a 3:64, 3:73 or a 3:91. I would love any feedback, Positive or Negative.