Project: Geo Metro boat tail prototype - 15% MPG improvement @ 90 kph / 56 mph

[MetroMPG]

Believe me: I've been sorely tempted to register and answer questions / correct misunderstandings and outright mistakes in these blog posts and comments about the tail. Alas, nope! I've got better things to do with my time - would rather spend it here at EM.

I figure if anyone's actually interested in the subject matter, they'll follow the link to the home page or to this thread (all the blog posts I've seen so far link to one or the other), and start reading. Then the light bulb will go on.

[Christ]

Originally Posted by MetroMPG

Believe me: I've been sorely tempted to register and answer questions / correct misunderstandings and outright mistakes in these blog posts and comments about the tail. Alas, nope! I've got better things to do with my time - would rather spend it here at EM.

I figure if anyone's actually interested in the subject matter, they'll follow the link to the home page or to this thread (all the blog posts I've seen so far link to one or the other), and start reading. Then the light bulb will go on.

Or, as is the case at times, the bulb will attempt to light, but immediately blow, further turning them off to the idea.

I've seen it. It happens.

People need 100 reasons to like something, but only one fail point to completely dismiss it without ever actually trying it out for themselves.

[3-Wheeler]

Originally Posted by MetroMPG

Believe me: I've been sorely tempted to register and answer questions / correct misunderstandings and outright mistakes in these blog posts and comments about the tail. Alas, nope! I've got better things to do with my time - would rather spend it here at EM.

I figure if anyone's actually interested in the subject matter, they'll follow the link to the home page or to this thread (all the blog posts I've seen so far link to one or the other), and start reading. Then the light bulb will go on.

Thanks Metro!! I was hoping you would stick to a reasonable way to handle this.

In life, those same people are looking for someone to badger or otherwise beat-up through words. And pointing them "to the source" will not change their opinion until they have traveled "that road" long enough to know that they are tired of beating a dead horse, so to speak.

Once that happens, they will be more open to others opinions and ideas, and thus listen to what you have to say.

Jim.

[thatguitarguy]

No real point in trying to convince people of the benefits of FE when gas is so cheap anyway. When it eventually climbs to European prices there'll be a lot of converts.

[Frank Lee]

I've always maintained that high prices and high prices alone (well... OK, govt mandates too) are what it takes to change behavior. Sure wish it wasn't that way

[3-Wheeler]

Hi Metro,

Say, after looking back at your posted data for the boat tail, that leads to a question.

Posted here is the page I am referring to:

http://ecomodder.com/forum/showthrea...-10691-25.html

Looking over several pages before and after this page did not give me a clear indication on exactly how you performed your testing.

Can you point me to a link or explain how you did it?

It looks like a ScanGauge or similar device was used to determine fuel usage through out the test.

What speed did you try and hold?

Did you monitor throttle position?

On the Insight, I can typically hold the TPS at 17 or 18 fairly steady for probably five miles or so, on a reasonably flat road.

If the throttle position changed during each leg of the run, then one could conclude that the wind speed would be a factor, and the run may have to be thrown out and/or tried again going the same direction each time.

Just some thoughts after performing some coast down tests, and getting some eye openers when looking at the small set of data so far.

Jim.

[Anaerin]

Expect a lot more eyeballs on this one, you just got mentioned on Make:

Make: Online : MPG boosting tail cone

[MetroMPG]

Cool - Make is one of my favourite sites.

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Jim: see http://ecomodder.com/forum/showthrea...tml#post145226

MPG was montored via ScanGauge. The Trip/Current Avg was reset when passing the same start marker, and the reading taken at a second marker.

The weakest point in my testing was that it was performed without cruise control (mine's busted). However: Avg Speed was also monitored on the gauge screen. With a lot of concentration, I was able to hold the target speed (1 mph resolution) through every run except for one on the level & straight route I use. On the one exception (1 out of 16 runs), the average speed was low by 1 mph.

[3-Wheeler]

Originally Posted by MetroMPG

...On the one exception (1 out of 16 runs), the average speed was low by 1 mph....

Hi Metro,

Hey thanks for clearing that up.

And when you said "1 out of 16 runs", that really clears things up.

That just goes to show that any type of fuel mileage testing requires a lot of runs, something that was not done during my coast down testing so far.

Jim.

[PaleMelanesian]

Metro - have you considered watching rpm instead of mph? There's a lot more resolution available there. 4 digits for rpm instead of 2 for mph.