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Old 12-29-2007, 09:02 PM   #3 (permalink)
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,459

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

MPGiata - '90 Mazda Miata
90 day: 55.97 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 67.41 mpg (US)
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Hi dremd, welcome.

I guess because diesel models are relatively rare in North America, people who own them tend to do the birds of a feather thing. Thus TDIclub, and clubsmartcar, etc.

I'm surprised more diesel folks aren't into modding (or maybe they are, and I just don't know about it). Everyone on this board knows of VW's diesel 1 liter car, that's for sure.

That said: aeromods and gearing are the way to go for highway fuel economy, if you're dead set on driving @ 70.

And I have read (maybe you can confirm or correct me) that diesel powered vehicles are even better suited to aero mods than gas SI engines. As you decrease load on a gas motor by helping it move through the air more cleanly, it needs less "throttle". Unfortunately closing the throttle probably also has the effect of shifting the operating range further away from the ideal BSFC zone.

My understanding is that because diesels don't have throttle plate restrictions and the associated pumping losses of SI engines, reducing engine load through streamlining will give a diesel car a larger relative return in efficiency.

What about gearing - do you know if you have any options there? (I put a taller final drive in my car, which helps most at cruise on the highway).

Anyway - I'm sure others will chime in.
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown

has launched a forum for the efficient new Mitsubishi Mirage - fuel efficiency info for Geo Metro owners - electric car conversion on a beer budget
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