[Uli_HH]

First of all ... +10 ... very good post !

Originally Posted by swamp2

No real disagreement with this. It is simply that BMW M have literally preached the virtues of a high revving, naturally aspirated, instantaneous throttle response, Motorsport inspired engine over a very long time period. With previous engines and reaching a peak with the current S65 design they have adhered to this philosophy. Neither the S85 from the M5 nor the derived S65 from the M3 were the inexpensive approach. At the volumes involved they were actually very far from the "accountants choice". These decisions were possible at BMW M at that time but are simply not possible today.

Its absolutly clear, that an high revving engine ist the most costly engine alternative ... and this not about development cost, but only about production costs. An high revving and daily driveable engine like the S65 needs many special and costly to produce parts ... at the time the S65 or better the S85 was developed ... the credo of the M-GmbH was to put "racing"(or racing like) engines in coupe/sedan style sportscars ... this fullfil the second M-GmbH credo "... only 20% common parts with an regular 3er series car ...".
The BMW AG tolerate this and because of the the relative high price increase for an M-Car over an regular BMW they make also profit with this cars -> every thing was right ... the the M-GmbH brings profit for the BMW AG and the customers get there desired cars ... unique - special - full of M(Racing) spirit ... bud sadly this has change in the recent year ... making profit now isn´t good enough - more (as much as possible!) profit is better and the only way to got (in the BMW AG opinion like much other branches).
Because of THIS and only THIS ... single kind developments like the high rev-engines for the M cars would be ruled out because of their high(higher) production costs ... if the same (needed Hp rates) could be achieved with and cheaper AG-based engine with much common parts ... and the BMW marketing branch gave this an green touch and make this to an "special" and M-worthy engine. What the M fans wants and get until today doesn´t interrest the BMW AG because the now ... at the end they think they sell enough M-Cars at the same high price but with much more profit because of the "cheap" engine.

No one of us really knows what mpg the S65 could achieve in an much lighter car as the F8x would be ... the main problem of the relativ low mpg numbers of the E9x M3 was the weight of this car, which isn´t really suited well to work with an high-revving enginge ... even the M3s mpg is much better than other cars in its class !

Originally Posted by swamp2

Again this discussion/debate began around BMWs motivations. To understand their motivations we simply must look at company strategy, their increasing focus on cost and part commonality. Most M owners want to have a special (i.e. rare) car (even if only slightly more special/rare than the base model). The M3/4 of tomorrow is becoming less special with respect to engines. And, again, these choices are not being made at the heavy hand of green politicians and governments. The volume of M cars is way too low to affect fleet average consumption in any appreciable fashion.

Again I can totally agree ... and the badest thing is that BMW decides not only for an cheaper engine than the great S65, but it must be "the cheapest" alternative that fullfil the hp-needs from around 450hp ... from more than one source from inside the M-GmbH you could hear that, the technican are willing to fullfil the demand about an turbo-engine as engine of choise for the F8x, but developed an unique and great 3.3ltr.V6 BiTurbo based on the S63Tü to fullfil the demands about power and better mpg for an F8x engine. And this sources all says all technicans prefer the V6 as the much better engine on M3/M4 demands ... but were overtrown by the cost reduction and profit maximation fraction that prefer the cheaper N55 based I6 for the new car - and the only advantage that the I6 has over the V6 was that it would be cheaper to produce than the V6 - development costs are not the problem, because thats are one time cost ... what counts are only the lifetime productions costs - the sources quote about <~1.000€ more per engine for the V6 ... an low disatvantage for an ~75K€ car, but too much if only the highest profit solution counts !!!

Greets Uli_HH