We'll have to except the numbers for what they are.It is what it is.
All the time,energy,and trouble to do the testing will be valuable just the same.
Sir James Dyson said he never learned a thing from his successes.It was the 'failures' which were the most valuable.
Carl Breer's team, Dr.Gino Sovran,and Hucho have all warned about limited results from drag reduction if the engine could not be maintained at a constant load to maintain BSFC.
I don't know that this is what's going on,but since it's been emphasized in the literature,it's something obvious that we must consider.
If the load is reduced,you're at even less part-load.The throttle body may be nearly shut as,unlike a Honda carbureted CIVIC,with three throttle bodies,the '07 is taking all air in through a single barn door.Barely cracked open.(horrible volumetric efficiency).
Without another gear to load the engine back up,the BSFC may have fallen off its island of peak efficiency.
Darin,we're indebted to you for going through the whole process and all on your own nickel.Lets see what we can figure out.
Since the US dumped the 55-mph speed limit,the CIVIC may be calibrated to run at higher posted speeds.If we had a baseline at 75-mph,we might see a completely different trend.
Thanks for all you do!
