Quote:
Originally Posted by MetroMPG
Yep.
See post #6 in this thread:
http://ecomodder.com/forum/showthrea...-camry-84.html
Nothing popped its head above the noise in testing skirts on a 2007 Camry Hybrid. Though I also admit to possibly poor testing (guessing that the car may not have been fully warmed up since the 2nd set of "A" runs was higher than the first set of "A" runs). |
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Thanks, MetroMPG. I read your whole thread and then looked back at my results. And although the second set of my "A" tests were *slightly* better mpg than the first (0.025), and maybe showing that "car warming up effect", I kinda doubt that can be taken too seriously (in my case), as I'm sure it's well within the margin of error.
But speaking of poor testing methods, my northbound run ends at the base of a slight hill where the mileage starts to drop and can drop 3 or 4 tenths of a mpg by the top. I try to catch it at a specific spot each time, and before "the change starts". But on my first set of "B" tests with the skirts, as I got to the end of my test section, I was distracted (the cell phone rang & I answered it, I think). Then it was "Crap - what's the trip average?!?!?" I caught it at 28.9 and dropping to 28.8, but I was also already past my end point and climbing the hill. So I wrote down 29.0, just guessing. All the "A" tests were 29.2 and 29.3, and the next 2 "B" tests were 29.2 and 29.5 for that nortbound run.
So, bottom line, maybe I should throw out the results of that first set. If I do that, the average of the remaining 2 sets is 29.8. Of course, that's a "small" data set of only 2 sets, too. - - and it only increases the "B" average one tenth of a mpg. Sooo...... (but it would move the improvement from 0.04mpg up to 0.14mpg, which is a huge difference there, I guess)
Another thing I noticed in your thread is it looks like you cut the cardboard & fit it INSIDE the wheelwell, making a more-or-less "flush" fit to the outside? In my case, I cut them a little oversized & just slabbed them onto the outer body surface with duct tape. That adds the thickness of the cardboard to the frontal area and also adds a rough "ridge" around the outline for the air to hit. So maybe those things tend to offset the gains from covering the openings? Gee, I sure wouldn't think so, but??????
I also read with interest the part about testing at higher speeds because the aerodynamic effect will be magnified. And I suppose the arguement could be made that unless I intend to drive around at 40 & 50 mph all the time permanently, a more "highway speed" test would even be more realistic for "real world" driving.
Bill
