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Old 08-27-2008, 08:59 AM   #71 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
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Blackfly - '98 Geo Metro
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Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
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The fact remains that the quality of the "supporting data" on which they're basing their claims leaves a lot to be desired. Why are they soliciting members of the public to generate even less reliable data for use in testimonials?

I wrote to Tony, the engineer who runs fuelsaving.info. He declined to participate in this thread (too busy - new family), but gave me permission to post his response after reading what's been offered here so far:

Quote:
I agree with your view that they don't have enough (any?) repeat testing to give statistical certainty. The sparkplugs.com dyno testing showed gains apparently well inside the test-to-test variability - including torque, where Pulstar claim to have a particular benefit.

The principle of increasing the spark power (though not energy) seems sound, but as I explain on my Web page, it's hard to see how that can give a big economy benefit compared to a conventional system in good condition. You could gain a percent or two through reduced misfires / partial burns, and that might be enough to justify the plugs for some people. But anything beyond that seems highly unlikely, not least because the ignition timing is optimised for the conventional system and a faster burn, even if theoretically helpful, would not give a practical benefit unless the spark was retarded.

As well as some better EPA-type economy measurements, Pulstar ought to invest in some burn rate analysis using in-cylinder pressure transducers. A competent engine lab at a university could probably do that for a few thousand dollars, and this would really prove (or not...) the theory that it gives a faster / hotter / "better" burn.

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