1580-1620 kg (EU)
Not less, not more.
But just think, M3 E46 weighed 1570 kg (EU) and had 343 PS. M3 CSL (E46) weighed 1460 kg (DIN) and had 360 PS. Now imagine a 1590 kg M3 F30 that has 450 PS and 550 Nm? It will be the fastest BMW ever (unfortunately, I say this be cause till today we still have no M1 Hommage).