View Single Post
Old 11-27-2007, 08:32 PM   #4 (permalink)
MetroMPG
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,134

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

MPGiata - '90 Mazda Miata
90 day: 53.56 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 61.98 mpg (US)

Fancy Metro - '14 Mitsubishi Mirage top spec
90 day: 58.72 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 64.03 mpg (US)
Thanks: 3,765
Thanked 6,574 Times in 3,409 Posts
04-04-2006, 10:37 Pm

well, screwed up the undertray test today.

i got in two bi-directional runs (of a planned three) with the tray on, when at the end of the 2nd run I heard some cardboard dragging. the rearmost panel had come loose and was hanging down across the width of the car "scooping" up air.

i don't know how long it was detatched since i didn't peek under the car from the time i left the house until the end of the 2nd run when i heard it hitting the ground.

so i pulled all the undertray off, hoping the rear panel only came undone at the end of the last run and that the full set of undertray runs wasn't affected.

i did 2 bi-dir "naked" runs for comparison, which produced very similar numbers:

52.93 mpg avg with the undertray (2 bi-dir runs)
52.38 mpg avg no tray (2 bi-dir runs)

speed was 55 mph.

Conditions at SUPN6 as of (1:00 pm EDT) 1700 GMT on 04/06/2006:
Wind Direction (WDIR): SSW
Wind Speed (WSPD): 6 kts
Wind Gust (GST): 7 kts
Atmospheric Pressure (PRES): 29.87 in
Air Temperature (ATMP): 41.2 °F

all of which means either the undertray has a very small effect on my car, or it was hanging down on both bi-dir runs.

of course, the only way i'll know for sure is to do it again crap.
__________________
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: Oops, I did it again! Bought another cheap, 3-cylinder Mirage. Mods in progress...
Ecodriving test: Manual vs. automatic transmission MPG showdown



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
  Reply With Quote