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Old 03-04-2013, 04:46 PM   #41 (permalink)
oil pan 4
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Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 11,266

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 141.63 mpg (US)
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With a gas engine you are always fighting the isobaric expansion (throttling losses) that starts off the otto cycle.
The only way I know to beat isobaric losses on a gas engine is to put a tiny effieient little engine in a car, like a twin cylinder 15hp briggs and straton and run it wide open on the highway your top speed will be about 60mph until you encounter a hill.
There is no way around it. If you get more air through the gasoline engine no matter if you use a free flowing exhaust or intake, you have to add more fuel to burn it properly.

See:
Cold Air and Ram Air - EcoModder
Increased compression ratio - EcoModder (click the popular hot rodding link at the end of the page)
Turbo charging - EcoModder
Water injection - EcoModder

Most things that give a gas engine more power typically lowers fuel economy, but on a diesel engine you get more power and more fuel economy most of the time.

__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
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