Looking to get a longer diff on my e30 m3

[lukeADE335i]

Thanks Wangan. My Dad is about to try a 3.25 small case in his 320i. I'm thinking it's too low, but he's mostly cruising on the highway on a flat road, so it should work ok. Going from a 4.10 to a 3.25 will make a big difference to cruising RPM.


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[m3j0n]

very difficult to quantify this; a gearing change will be much easier to compare.

Fuel data for Average combined Fwy/local driving (prior DD's)

1998 M3 3,23->3,46 = decrease 24-25 MPG to 22-23 MPG
2003 325i 3,15->3,46 = decrease 25-26 MPG to 23-24 MPG
1992 525i 3,23 ->3,15 = increase 23-24 MPG to 24-25 MPG

the more modern m54 engine with is double vanos and can bus electronics is much more conservative on fuel on freeway cruising; its 29-30 mpg.
Obviously 3200cc vs 2500cc is another issue regarding mpg.

Choose the final drive that suits your desired MPG for the kind of driving you enjoy. Stock BMW is always good

can you pm me a quote on the labor to build me a 3.25 LSD?

[m3j0n]

just took the e30 m3 out for a drive and, while the acceleration is nasty, I hit top speed very fast and highway driving is almost unbearable over long distances.