They are probably trying to make sure the detuned M2 with the S55 doesn't outrun the M3:
doublespaces Administrator Oct 18, 2016 9,310 4,342 0 AZ Ride 2009 E93 335i Dec 23, 2017 #1 They are probably trying to make sure the detuned M2 with the S55 doesn't outrun the M3: