gale

My '91 735 has a 4.27 differential and I'm quite pleased with the overall performance. It offers significantly better off-the-line acceleration than the 3.61 although I do suspect that fuel economy suffers as a result (but as you say this is no big deal). Most of my driving is also in the city but the revs don't seem to be bothersome when cruising on the highway.

I'm trying to eek out a little better acceleration from my 735i for in-town driving since that's where I use it the most. Correct me if mistaken but didn't the 735iL change from 3.64 to a 3.91 rear end ratio around '90 or '91? Has anyone else made the swap? I think e34 M5's also used a 3.91? but would probably be more scare.

I'm not too concerned about the impact on fuel milage increased or highway rpm's since most of my driving is in-town & on an average I only put on 5k miles per year. I realize going from 3.64 to 3.91 isn't a dramatic change percentage wise but a 4.10 or 4.27 seams a little too aggressive. Any feedback appreciated.

gale
92 735i
148k