[MeteorGray]

My Mazda3 is run via computers and related electronic drive-by-wire throttle control, and even so I use a mechanical throttle stop to maintain consistent speed under consistent conditions.

With the WOT mechanically set via the accelerator-to-floorboard gap as determined by the throttle stop, I can maintain a selected speed on the highway that varies only due to variations in the grade of the road and the wind direction and velocity at any given time. This is to be expected, since the throttle only delivers power according to the throttle setting of the throttle stop. The computer drive-by-wire setup does not try to compensate for these variations in road grade and wind, since to do so would mean it would independently deliver variations in power that the driver isn't commanding via the throttle; that would be what a computer-driven cruise control does in order to maintain a commanded speed. My car doesn't have cruise control.

So, I guess I'm not understanding how a mechanical throttle stop doesn't work for testing changes in the aerodynamics of modern computer controlled cars with drive-by-wire throttles.

Unless, of course, hybrids truly are different. I don't have a hybrid.