Originally Posted by Blue Streak
Look for the "flex finder" mobile device (iPhone) app for E-85 station locations. JB4 does have provisions in mapping for that fuel if mixed to about a 30-50% E-85-gas mix. Understand also that the N54 engine is on model years 2007-2008 (and all 335is models), but the N55 engine is in 2009 through current models. N55 is excellent, but N54 has more tuning potential for twin turbo boost potential at high rpm and power, where the N55 loses efficiency at that range.
N54 isn't only 07-08, it is 2007-2010 YM.
And Blake, I would make sure you get one with sport and oil cooler.