Diff question

[aimlessrock]

Folks, i have a quick questions on diffs my cabby has a 4.27 small case diff which is in fine order, Im not a drifter and do local miles and the odd country drive when the sum is out..(very rarely!).

Im more into mpg rather than speed and wondered if a change in diffs would assist in this vein?

would appreciate any advice.

Cheers

Gary

[Brianmoooore]

Definitely would! You haven't said what engine you have, but if it was factory fitted with a 4.27, then I assume it's one of the smaller ones. 4.1s are readily available in small case, or you could go to a 3.9, which will most likely be a medium case, but will still fit right in.

[aimlessrock]

thanks Brian, sorry she is a 320i 1989 cabby (chrome).

hmm, so a 4.10 would be a good compromise in that case from a 4.27?

Regards

Gary

[Brianmoooore]

For a 320, I'd even consider a 3.9. They were used by 320 saloons immediately before the facelift, and lower again were used earlier.
If you want real fuel economy, then LPG is the way to go.

[aimlessrock]

Thanks again Brian, LPG is something on my mind long term, but i only do about 2-3K miles in the cabby a year so its quite low on the list.

Thanks again

Regards

Gary

[Silverfang]

Had a 320i myself, went with a 3.91 LSD, which did help a bit with the old MPG, along with a Speedtouch chip as well.