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Old 12-31-2007, 08:08 PM   #15 (permalink)
EcoModding Apprentice
Join Date: Dec 2007
Location: Melbourne
Posts: 152

The Mighty Mira - '92 Daihatsu Mira
90 day: 61.32 mpg (US)
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Originally Posted by SVOboy View Post
Pretty sweet! I'm endlessly impressed by your ability to make improvements and actually get out there and collect the data.
Thanks... although coast down testing is so difficult to do it's almost impossible. I'd treat any figures with a large grain of salt.

With wind, elevation, and temperature all playing a part, it's very difficult to get it right. Especially wind. Every cyclist knows what it's like to get a gust of wind in the face, how that will slow you down very quickly (or enable a longer coast). But you just don't feel it in the car.

Crosswinds are also lethal - wind can be coming from almost any angle except about 30 degrees or so directly behind, either side, and still slow you down.

I should get myself some sort of altimeter before I even do a coastdown test via eyeballing.

However, I do know that there is a definite improvement to all my modifications, and that it is sizable. I can tell that by the sorts of hills I can coast down now and maintain or increase speed, and the way that my FE has improved to something like 3.7l/100km compared to 4.6l/100km highway. And that's with a combined cycle drive. If it was solely highway, it would be better than that no doubt.
"Every body perseveres in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by force impressed." - Isaac Newton
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