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Old 07-26-2012, 12:13 PM   #14 (permalink)
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Join Date: May 2011
Location: Indiana
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White Whale - '07 Dodge Ram 2500 ST Quad Cab 2wd, short bed
Team Cummins
90 day: 37.68 mpg (US)
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There's some value in both Cd and Cd*A. Cd*A is what does ultimately determine the aerodynamic drag force, however, Cd allows comparison of different sized vehicles. For example, it makes no sense whatsoever to compare the Cd*A of a tractor-trailer to that of a small passenger car, however, comparing Cd is a fair comparison.

It also makes sense for scale testing in wind tunnels. Cd stays the same for the scale model and the full-sized version, Cd*A obviously changes (because of A).
Diesel Dave

My version of energy storage is called "momentum".
My version of regenerative braking is called "bump starting".

1 Year Avg (Every Mile Traveled) = 47.8 mpg

BEST TANK: 2,009.6 mi on 35 gal (57.42 mpg):

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