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      02-22-2010, 08:12 AM   #2
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amk2912's Avatar

Drives: '10 X5 40d & '12 F10 520d
Join Date: Dec 2007
Location: Perth

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Originally Posted by TrackRat View Post
Minimal throttle position causes high engine pumping losses. BMW conducted extensive testing years ago and determined that WOT in a higher gear delivered better mpg than low throttle opening in a lower gear for acceleration. At a constant speed like on the hwy. running the engine rpm close to the torque peak in an N/A engine delivers the best mpg, (the lowest BSFC). In a forced induction engine you need to find the balance point for boost, throttle opening and engine rpm, which can vary considerably based on the vehicle and engine.
Thanks for that - brilliant info! Truly the S65 is built to perform! I can see it now...

"Sorry Officer I was trying to save fuel by driving really fast!"
2012 BMW F10 520d M-Sport
2010 BMW E70 X5 xdrive40d