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Old 11-28-2007, 10:00 AM   #7 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,235

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.8 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)

Fancy Metro - '14 Mitsubishi Mirage top spec
90 day: 55.99 mpg (US)
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Using the aero/rr web tool I made based on Dan's spreadsheet, my car theoretically gets 56.7 mpg (US) @55 mph (Cd: 0.34, frontal area sq.M: 1.858, @ 25C, default fuel & engine eff. values). That's actually not far off my actual FE at that steady state speed.

Removing one mirror: Theoretically, using the more conservative GM numbers, taking off a mirror reduces the Cd by 0.015 and the frontal area by about 0.0375 sq. M.

That improves my 55 mph highway FE to 59.64 mpg (US), or +2.94 mpg (US) / +5.19%.

That's a gigantic improvement in my books, if it's true.

EDIT- I mistakenly used the least conservative numbers. The Chalmers report has the more conservative range. So I'm guessing the actual effect will be less than 5.19%
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EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
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