Hate to bump this thread, but a couple of days ago I had the 550i (xdrive) and I was able to beat an e90 m3 from a roll.
I know I have a lot more torque so at the begining I would pull away but as we kept going he wasnt gaining on me at all if anything I was pulling away.
I highly respect the m3, but unless its from a dig and the m3 gets a super good launch I doubt it could beat the 550i
By the way I own a tuned 335i and my best friwnd has an m3 and I know the speed of the m3 and whenever I drive the 550i you can tell its faster in a straight line.
The 335 will pull on the m3 but at high speed the m3 beats it, however the 550 doeant have a small engine with small turbos that run out of breagh, the 550 keeps pulling.
Once again this is in no way to bash the m3, I love it and I mean cmon at the end of the day theyre both bmws so we gotta love em.
Edit: also want to add in, car amd driver tested the 550i doing 0-60 in 4.5 and 1/4 in 12.8
For a big heavy car it moves!