[aerohead]

Originally Posted by Ecky

I skipped over a few pages in this thread, so this may have been addressed, but my ultimate questions are these:

1) Does generating lift necessarily generate drag? All else being equal? Certain you can take an aerodynamically dirty vehicle and clean up the wake in a way that creates lift and may not add drag, but that's not what I mean.

2) If creating lift *does* create drag, wouldn't it be the case that, at the speeds where this lift matters, rolling resistance is a much smaller component of total drag? At 30mph/50kph, where rolling resistance is dominant, very little lift would be generated. At 80mph/130kph, where aerodynamic drag is the vast majority of total wasted energy and rolling resistance approaches negligible, is it worth adding more aero drag to cut rolling resistance?

* If we can agree to analyze a specific vehicle, the math will answer our questions.