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Old 01-06-2008, 10:18 PM   #20 (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

3 - '18 Tesla Model 3
90 day: 152.47 mpg (US)
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Quote:
Originally Posted by Smoky View Post
Be careful with the boat tail trick. Many times this will make the car less efficient. Many of the aero scientists I have worked with really push for a 'chopped off' rear end to to help meet the aero requirements.
I've never heard of a boat tail making a car less efficient. It's just that the advantage is proportional the the area where the boat tail shape terminates. In other words, since the lines on the usual car result in flow separation over the entire back half, having a sloped back end so that the flow doesn't separate over the entire rear profile is an improvement. The Prius would probably be more efficient w/ more of a boat tail, but the improvements would decline asymmetrically compared to the increase in length and drop in usable area.
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