differential 3.91

[markus_74]

Hello,

Need advice on 325i differential. I know that is 3.64 and 3,72 but it is difficult to find locally here
But my friend offer me 3.91 lsd final gear.

Can i apply this to 325i and what is pro and cons?

He said it will fit to my standart case, but in my opinion this should use medium case?

Thank you
Markus

[Brianmoooore]

3.91 is standard on a 325i touring. Gives marginally improved acceleration at the expense of marginally decreased MPG when compared with the 3.72.
Is your 3.91 not a medium case diff.? (188mm diameter crownwheel.)

[markus_74]

3.91 is standard on a 325i touring. Gives marginally improved acceleration at the expense of marginally decreased MPG when compared with the 3.72.
Is your 3.91 not a medium case diff.? (188mm diameter crownwheel.)

I'm not sure which differential now fitted to my car but my car is originally m40 318i sedan/limousine and also i don't know what the ratio it has.

But may be small case 4.10

Also i will use getrag 240, so what is best combination? Plus 3.73 or 3.91?

How much is average fuel consumption by using 3.91? Does it is greater? Because i use it for my everyday car.

[mikesurf]

3.91 is the best... in France it's a special 325i sport serie "is" with the lsd 3.91