Hi,
here're some diff ratios...
316i (M43) - 3,38
316iA (M43) - 4,44
318i - 3,45
3,46 Südafrika
318iA - 4,45
318i (M43) - 3,38
3,46 Australien / Südafrika
318is/ti - 3,45
318is/tiA - 4,44
318is/ti (M44) - 3,38
3,45 USA / Kanada
318is/tiA (M44) - 4,44
320i - 3,45
320iA - 3,45
4,10 USA / Japan
323i - 2,93
323iA - 2,93
3,64 Japan
3,91 USA / Kanada
323ti - 3,07
323tiA - 3,23
325i - 3,15
325iA - 3,15
3,91 USA / Kanada
3,73 Japan
3,64 South Africa
328i - 2,93
328iA - 3,07
3,91 USA / Kanada
3,46 Japan
M3 - 3,15
M3 (S50B32) - 3,23
318tds - 2,79
325td (ab 3.92) - 2,56
325tdA - 3,23
325tds - 2,56
325tdsA - 2,56
there're nearly no differences between a sedan(i) and a coupe(iS). The diffs, the accelaration and the weight are the same and the weight too. But you can change the diff of your car...
I've a 3,45 from a M50B20 in my 325iS and the accelaration is pretty good
greets
Looky