Will putting a 318i diff in my 316i make it slower????

[Finto_316]

Hello,
i have been told that when you put a 318 diff in a 316 it makes the gears longer therefore mqking the car slower?

But i looked up on the internet bmw e30 diff ratios and it said only 1990 318's ar 318 is's which have a bigger ratio?

Can ane1 verify any of this?
Thanks

[charlE30]

Have a look at this http://en.wikipedia.org/wiki/BMW_3_Series_(E30) for diff ratios

What does the tag near the speed sensor on the diff say? if your original diff was 4.45 and you then fit a 4.10 the car will be slower in acceleration but have a higher top speed.

HTH