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Old 05-07-2008, 06:09 PM   #35 (permalink)
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
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Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 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: 52.48 mpg (US)
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Originally Posted by Dan. View Post
Always fill up at the same station - And no, it's not a numbers game. Has to do with the fuel trim tables in most cars
Thanks, Dan - I'll add it. I presume the effect could go the either way though: if you happen to switch to a fuel brand with a lower energy density (from a previous high energy density fill), you'll have "lean burn" advantage until the O2 sensor finishes adjusting the fuel trim.

I wonder about the cold gas tip though. Not questioning the physics, of course. But is it more of an economics issue than an efficiency issue? The difficulty is how do you choose to buy cold fuel vs. warm? (My reading on the lateday vs. early morning fill timing is that underground tanks are mostly unaffected by atmosperic temp fluctuations.)

I love these tips that split hairs. Their impact may be somewhere between nil and tiny, but the fact that people are interested enough to consider them is very, very cool!

They're also the kinds of tips that cause those who are anti-hypermiling inclined to yell and pull out their hair.
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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