BSFC for 250-HP Engines - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  BSFC for 250-HP Engines

search | FAQ | profile | register | author help

Author Topic:   BSFC for 250-HP Engines

jimh posted 02-06-2011 08:56 AM ET (US)
The best way to compare the fuel efficiency of engines is to use their brake specific fuel consumption (BSFC). Comparisons which try to use boat speed data and fuel flow rate data are not particularly interesting because there is tremendous influence from the boat and propeller on those data. Fuel consumption at a particular horsepower is a function of the engine, and tends to eliminate influences from the boat and propeller.
Using published data from manufacturer websites, I compared the brake specific fuel consumption (BSFC) of some 250-HP engines with the following method:
--found fuel flow data at maximum throttle for various 250-HP engines
--averaged a random sample of reports
--computed BSFC using 6.25-lbs/gallon for gasoline fuel
--computed BSFC using 250, that is, the rated horsepower, as the horsepower
The results are as follows:
Average Brake Specific Fuel Consumption
EVINRUDE E-TEC 250-HP = 0.6125-lbs/HP-hour
MERCURY OptiMax 250-HP = 0.666-lbs/HP-hour
MERCURY OptiMax 250 ProXS = (no data available)
MERCURY VERADO 250-HP = 0.6615-lbs/HP-hour
Conclusion: The E-TEC has the best fuel efficiency. The Mercury OptiMax has the worst. The Verado is slightly better than the Optimax. The OptiMax sample is very small.
Here is the actual data I used:
250-HP Outboard Engine Comparison
YEAR RPM GPH Source
Evinrude E-TEC 250-HP
2011 5800 22.25 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE793.pdf
2011 5550 22.75 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE805.pdf
2010 5700 22.95 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE779.pdf
2010 5600 23.45 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE782.pdf
2010 5800 26.10 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE761.pdf
2010 5800 23.10 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE786.pdf
2009 5875 26.45 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE787.pdf
2009 5750 23.40 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE679.pdf
2009 5858 25.85 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE692.pdf
2008 5825 21.65 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE703.pdf
2009 5600 26.55 http://www.evinrude.com/Content/Pdf/neutral/performanceReports/PE769.pdf
AVERAGES
**** 5741 24.05
BSFC for 250-HP and 6.25-lbs/gallon = 0.6125-lbs/HP-hour
Mercury OptiMax 250-HP
2008 5800 20.6 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=351&
2008 6000 26.7 http://www.mercurymarine.com/engines/engine-tests/third-party/?ID=88&
(Only two tests available. The in-house data is ignored because it is completely out of range)
AVERAGES
**** 6000 26.7
BSFC for 250-HP and 6.25-lbs/gallon = 0.666-lbs/HP-hour
Mercury OptiMax 250 ProXS
No test data available
Mercury VERADO 250-HP
2008 6100 27.70 http://www.mercurymarine.com/engines/engine-tests/third-party/?ID=99&
2009 5900 26.4 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=451&
2010 6280 26.50 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=472&
2010 6200 26.50 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=462&
2008 6400 26.20 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=328&
2008 6100 27.00 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=329&
2007 6182 26.55 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=183&
2007 6280 24.50 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=185&
2007 6060 26.70 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=187&
2007 6046 26.55 http://www.mercurymarine.com/engines/engine-tests/boat-house-bulletin/?ID=189&
AVERAGES
**** 6155 26.46
BSFC for 250-HP and 6.25-lbs/gallon = 0.6615-lbs/HP-hour

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.