Quote:
Originally Posted by aerohead
If doing development work on a specific vehicle, you'd be advised to stick with the same tunnel.
If doing development work on a specific vehicle, Cd 0.299 would be significantly different than Cd 0.290.
The rotating wheel drag on the Tesla Model S was delta- Cd 0.009.
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Yes that's right.
But that's not the point you were making in the original post. You were comparing the drag figures of two different cars, measured in two different wind tunnels, to three decimal places. You said:
"Cd 0.137 ties Ford's 1985 PROBE-V concept car."
Interesting, but I wouldn't get too excited by Cd figures to three decimal places. A top aerodynamicist suggested to me that taking three decimal place Cd figures as gospel was basically a fool's errand. (As in, test in different wind tunnels and you'd likely get a larger variation than this.)