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Old 08-23-2009, 05:19 PM   #43 (permalink)
roflwaffle
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Join Date: Dec 2007
Location: Southern California
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Camryaro - '92 Toyota Camry LE V6
90 day: 31.12 mpg (US)

Red - '00 Honda Insight

Prius - '05 Toyota Prius

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Quote:
Originally Posted by Frank Lee View Post
I'm thinking no.

I'm thinking the biggest reason P&G works is simply due to the percentage of time the engine is off.
Perty much.

The only engines I can think of offhand that have really nice BSFC ovals are newer heavy duty ones (I think thi is from a DT 466), and even those can see a ~25% increase in FE through judicious "load leveling", so to speak. Older diesels, as well as most gassers, can still see a significant (greater than 25%) increase in efficiency by trading consistent low load operation for periodic high load operation, given the same vehicle energy requirements of course. Obviously, if the operating conditions permit it, and it's available, taller gearing can do the same thing w/o the hassle, but that isn't always an option.
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