BEST DIFF for long daily drive?

[AndersLS]

Hello guys.......I have got hold of an 2.5l engine, that I will dropping in soon......whats the "best" diff for long drives? 3.73? 4.10? 3.64? others?
Please ....all info is good!

[E30Mark]

It's going to depend on what gearbox your going to use...

If your just looking for low RPM cruising, then get the lowest geared diff you can find, ie a 3.64 ratio will rev lower than a 4.1, but then i guess you know that....

The gearing is a compromise, the lower the ration, the lower the acceleration!

[iDreamBeemer]

was going to put stuff in but Mark beat me to it!

Do a seach in the Tech section with 'LSD' and you'll find loads of previous posts with more info.

[Brianmoooore]

3.64 is the one to go for.

[Zayyan]

whats the "best" diff for long drives?

If the state of your fuel prices is like ours, probably one attached to a diesel

[Lordschleife]

Yeah 3.64 would be your best bet for that

[CaesarBob]

Or you could get real silly and use a 2.93 from eta. Trouble is you'd probably struggle to beat a milk float off the lights.

[m-dtech]

i got one from a 1987 bmw 525e.

its yours for £50

drop me a pm if interested.

[Simon13]

for god's sake don't fit a 2.93. Get a 3.64 as said, makes a 325i drive nicely and gives it longer legs than a 3.73 or 3.91.

70mph@2500rpm beautiful bernard in 5th

[Brianmoooore]

If the state of your fuel prices is like ours, probably one attached to a diesel

You can get petrol performance (and sound), with far better than diesel economy by running it on LPG.

[jonb]

yes.

you will be mad to fit the 3.25 from a m3. the 2.93 will be a joke.

longer legs doesnt mean better economy.

3.64 is the perfect match.

[jonbuoy]

3.25 LSD!
I'm going to change mine to 3.64 LSD as i would prefer more accelleration but it don't take long to get there!

80mph 2900rpm in 5th gear

100mph 3rd at 6000rpm
120mph 4th at 6000rpm
140mph, so far, not pushed it any further yet ........in 5th........5000rpm
Had to slow down, was coming up to some serious bump's on the M25

I don't need to go any faster or push it to that limit again as i can officially say i've been there (Speedo reading) so mine will be up for sale soon if that's the sort of 70 - 80mph rpm your after?