Originally Posted by swamp2
But is the F80 vs. E90 number (difference) even known precisely and firmly yet?
No. The only thing I got to know 1-2 years ago is that the M3 F80 would be lighter than the M3 E46. I don't think by that much, that is why I speculate at these approximate numbers :
M3 E9X : 1650 kg (EU)
M3 E46 : 1570 kg (EU)
M3 F80 : 1550 kg (EU)