I have to laugh at you fools who pull a discussion into a side ditch and then insist others are evading issues because we choose not to follow you into the ditch. Invariably you claim that you have asked several questions to which we have not responded.
Let me make this clear one more time. Hopefully, some osmotic process will occur that will cause it to sink through your incredibly thick skull.
billbears said:
"And in actuality I get better gas mileage at 70 than I do at 55."
You responded:
"Physically impossible. Air drag increases with the cube of velocity."
I rebutted:
"Nonsense. My Jaguar XK8 is in sixth gear turning 2100 RPM at 90 MPH. It is in fifth gear turning 2800 RPM at 55. That's a simple matter of gearing and physics. My instantaneous fuel economy at 70 MPH on flat ground is around 35 MPG. At 55 it is around 26 MPG."
Either realizing that you had screwed up, or being completely clueless, you danced off on some tangent about the top of the RPM curve and wind resistance. Now you're excusing yourself with babble about "95% of all cars."
I repeat, your assertion that is is physically impossible for billbears' car (or my car or Spktyr's car) to get better fuel economy at 70 MPH than at 55 MPH is nonsense.
You are welcome to rant at length about wind drag and RPM curves, it is completely uninteresting to me and not germane to the point.
I never made this claim. As you have repeatedly ignored or chosen to overlook, I have admitted that I did not make the proper exception for the class of car you drive. In the general sense, fuel economy is directly proportional to the horsepower developed by the engine which is regulated almost entirely by wind drag. This is absolute. You are out to prove something that has not been stated, or you bask in ignorance and are really proud of it.