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Old 02-10-2009, 11:26 AM   #20 (permalink)
ConnClark
DieselMiser
 
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Join Date: Jun 2008
Location: Richland,WA
Posts: 985

Das Schlepper Frog - '85 Mercedes Benz 300SD
90 day: 23.23 mpg (US)

Gentoo320 - '04 Mercedes C320 4Matic
90 day: 22.44 mpg (US)
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Quote:
Originally Posted by Daox View Post
Nice calculation ConnClark. However, I once calculated efficiency of an engine using EPA mileage for my Matrix and Paseo. It came out to 13% for each. 23% would be a HUGE increase. Ironically, thats about what it came out to be when I plugged in my summer mileage for the Paseo (which wasn't too far from 100% above EPA). There are pretty huge gains to be had for supplimenting or replacing gasoline for electric power.
The 23 % efficiency is for the engine alone. Using mpg you have to account for transmission, drive line, aero, rolling friction, etc...

some more efficiency factoids.....

A typical new car engine is more like about 25 to 28% efficient. A diesel is about 30 to 45%.


A modern supercritical Rankine cycle power plant is about 42% at best. (if your power plant is more than 10 years old don't plan on this being the case)

clean energy ( geothermal, solar, wind, hydro electric, and biomass) made up only 7% of US power sources in 2006 and 90% of that was biomass and hydro electric based.
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