3.15 LSD vs 3.91 LSD differential, whats your opinions..

[trBo328iKevo]

I mean i'm about to pick up either 3.15 LSD differential or 3.91 LSD differential for my 3 series, i just haven't decided which route to go with? I mean any suggestions & why should I go with which one? Because i mean my car has almost 100,000k miles on it & i believe it's time to change the differential & driveshaft so i need opinions please.

[Spahrman5]

if its a 5 speed, i wouldnt want to drive it on the highway with 3.91 gearing.

[SpeedTheory]

The 3.15 will make your car accelerate like a Prius, and the 3.91 will make your car swallow gas like a hooker guzzles....well, you know. Get something else. 3.73 or a 3.6*

[328ischef]

you should check into a 3.23 or a 3.38, although they will cost much more, hard to say

[ZeitgeistCrew]

The 3.15 will make your car accelerate like a Prius, and the 3.91 will make your car swallow gas like a hooker guzzles....well, you know. Get something else. 3.73 or a 3.6*

i got a 2.93 open and i promise it'll smoke a prius.

what are you sayingt that the 3.15 wouldnt help?

[blue96328i4dr]

lol- interesting overstatement there... A prius- sheash.... Oh, I see- your in a 318, makes sence now. -sorry, just playing.

My 328's stock @ 178k (you didn't mean 1 mill miles did you?), my diff and drivshaft are doing fine- though it's time for a new guibo. Mileage alone can't really be used to determine when to replace stuff. -I know a guy with a 328 with 400k on it still on original driveshaft and diff- though the bearings where redone @ 250k on both.

I'd say get a 315 unless you're rarely on the hiway- or otherwise over 70mph... 315 will raise your rpm on hyway ~200rpms, you'll gain a bit of accel, and lose a bit of mileage. seams to me, it's more practical then others- I do alot of hyway driving though. -I'd even buy a 2.93 lsd if I could pick one up cheap- IMO the m52's got enough torque to remain respectable with stock gearing; and the rpm at hiway speed = your engines longitivty & fuel mileage.

[Spahrman5]

ive got a 3.15 and i love it. Car still drives like it used to on the highway, but it definetly accelerates harder. For a little more punch, go with the 3.23

[waterboy420]

Which cars had a 3.15 LSD? 325 I believe?

[Spahrman5]

95 M3
e36 325s with winter package

[Pink Floyd]

I love my 3.23 LSD - anything shorter would be death on the highway. Right now at 90 MPH I'm at 4K RPMs which I feel is tolerable, especially when you take into account the around-town acceleration.

[Kevin325i]

Cruising around town wasn't too bad with the 3.91 and on the highway at 75-80 i was still getting 26mpg. Wasn't really all that bad and it pulled very hard through all the gears.

[beatniks325]

e36 325s with winter package

only before traction control remember

[Zaks]

i vote for 3.15 unless you race a lot. i'm looking to get a 3.15 or 3.23, i don't really care but if i find a 3.23 for a good price then i'll go with it.

[5speed300]

Kevin I read your for sale thread for your 3.91 and saw that you were looking for a 3.38. If the 3.91 wasnt that bad, why the switch to a lower ratio? Just got sick of the shortness of teh 3.91?