Quote:
Originally Posted by Nerys
I do not doubt the data. but part of good science is being able to reproduce data which is what I tried to do.
steady state or not 15% improvement "should have" shown up as more than a 1 or 2% difference in 400miles of driving where each leg is 54miles 1:20 minutes (basically that times 6)
if even 50% of my trip is relatively steady state (its much more than that but I don't have hard numbers) that means I should see at least a 7-8% difference.
then again It could also be my car. I might have something failing thats dragging me down (lately I have been maxing at 40-42mpg but its also been REALLY cold and really windy the last few weeks which might explain that.) so I have not tried to do it again till I have more consistent figures. because I damned well would slow down 10mph if it meant I could gain even 5% FE improvement :-)
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One of my SAE papers took EPA Mobile Sources to task,claiming that a 20-mile warm-up before mpg testing was not adequate,and that in their own testing,reproducibility could not be achieved without 45-miles of driving.
It could be that the 54-mile test legs are not adequate.
Another paper claims that in an 11-mile cold-start commute,that the mpg in the last 6-miles is 50% better than the in the first 5.
Beyond a single variable during testing,making sense of the results can sometimes require the use of a super-computer and very sophisticated programs.