# BSFC - Brake Specific Fuel Consumption



## DocHoliday (Jul 18, 2008)

Since a lot of the discussion on here relates to the interplay of performance and mpg, I thought this article may be of interest to a few of you:
autospeed.com

A pint goes to the first person who can post BSFC maps for a Ducato 2.8JTD and a Mercedes Sprinter 312.


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## sallytrafic (Jan 17, 2006)

Assuming the two models are diesels I guess BSFC maps don't really matter for the reasons given in the article.


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## DABurleigh (May 9, 2005)

My recent and fascinating experience experimenting driving an economical diesel with instantaneous and average fuel consumption readouts would suggest things are quite straightforward in practice. Generally speaking, don't go over 2000 revs in intermediate gears (i.e., change up early), and, surprise, surprise, if you keep your speed down in top to 2000-2500 revs, you maximise fuel consumption and keep the notes in your wallet instead of fluttering out the exhaust pipe.

Dave


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## DocHoliday (Jul 18, 2008)

*Tuning chips?*

Dave, it must be good to have those fuel consumption figures on display, but only modern units have that as standard and retro-fitting can be expensive.

I'd be interested to know how tuning chips or remapping affect the BSFC curve, if at all. I bet most of the tuners haven't measured it.


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## Bagshanty (Jul 24, 2005)

I generally drive at 56 mph, because that is 2500 rpm on my short 5th gear (I replaced the long 5th a while ago). 2500 is the design peak revs for the 2.3JTD engine, which I reasoned would be the best match of performance and economy. It is also a much more relaxing drive, I've found.

So it was interesting to see that the lowest bsfc was between the highest torque, and the point where the torque curve crosses the power output curve (albeit for a naturally aspirated petrol engine)


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