1. V8 Biturbo
Least likely IMO. Think of the past, M3s typically 2 less cylinders than M5. Also, does not fit in with new corporate direction of "Efficient Dynamics" - this option will not be sufficiently efficient.
2. Development of N54 - no forced induction.
2nd least likely. First, not special enough. Second, I don't expect M engineers will get the power/fuel efficiency combo they want w/ this design.
3. S63 - probably too big for M3 (weight etc).
4. Mod S63 - 6-cyl.
Plus: can likely get the hp/mpg combo. Negatives: V6. But when we think about it, the E9X M3's V8 set the stage for this strategy of downsizing the M5's donk. Also, development costs / time lessened. Have not seen reviewers complaining about the S63 - except that it does not rev like the prior M5's V10. Same will likely be said of next gen M3/M4. I think this model is pretty likely.
5. New gen IL6 with tri-turbo (with electrical pre-lim spool to eliminate drag). Say 3.2 - 3.4L. My preferred option: would get to 450 hp and maybe 25-30% more efficiency than outgoing V8. Also possible.
Don't get me wrong: I love my M3's V8. Just that with new fuel targets, globally, the writing is already on the wall. Tech must move on.
Just thinking of something not so witty
///M3 E92 '09 Jerez Black | 6MT | Ext Fox Red | Tech | Prem | 19s |Heated Seats | iPod |Smartphone | Euro Deliv June 09
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