I don't trust any of the "published" 0-60 times except for Car and Driver or Road and Track. In doing comparisons among vehicles I only compare numbers obtained by the same publication. I think C&D is a tick faster than R&T.
C&D tested the E60 550i at 5.0 seconds. The F10 weighs around 300 lbs more or an increase of 7.5%. The F10 has 407 hp compared to 360 for the E60 or an increase of 13%. So, the F10 should be faster. Even more important in low speed acceleration is low end torque. Here the difference is much more dramatic. 360 lb ft for the E60 at around 3400 rpm. 450 lb ft for the F10 at ONLY 1750 rpm! This is an increase of 25%! And at a much lower rpm. This will make the F10 MUCH faster 0-60 than the E60. If the E60 is 5.0 sec, the F10 should come in at around 4.6-4.7 sec in the C&D road test. The xDrive version should be around 0.1 to 0.2 seconds faster as it was on a recent comparison test between the 750i vs the 750i xDrive.
BTW, C&D tested my E39 M5 at 4.7 seconds and it weighed 4000 but only had 369 lb ft of tourque. So, the F10 550i should be about the same or a touch faster.
2015 i8 Tera World Protonic Blue