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Old 05-11-2020, 06:17 PM   #9 (permalink)
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Originally Posted by aerohead View Post
The conclusions drawn in the peer-reviewed technical papers are contextual.I believe you touch on that in your book.
Well, of course. But 'contextual' is the whole issue here: the context is that in some cases, full wheel covers increase drag. Isn't that the point?

Originally Posted by aerohead View Post
I didn't give any advice that I know of without caveats.
I am sorry, but I have seen lots of advice here - including from you - that is stated without any caveats whatsoever. Here's an example that was being used in a signature:

"At 55 mph, a 10% drag reduction translates to a 5% increase in fuel economy. At 70mph,a 10% drag reduction translates into a 6% increase -Phil Knox (Aerohead), Aerodynamics Seminar #2"

No caveats there.

(Nothing on what proportion of total drag is made up by CD vs rolling resistance - which is car-dependent? Nothing on the change in engine efficiency - BSFC if you like - as the rpm changes? For a discussion of this sort of thing, see Barnard, Road Vehicle Aerodynamics Pages 54-55, and Stone, Motor Vehicle Fuel Economy, Page 136.)
Modifying the Aerodynamics of Your Road Car

A really good book that should be added to the library of everyone working in automotive aerodynamics, as well as those making car aero modifications at home. - Rob Palin, former Tesla aerodynamicist

Last edited by JulianEdgar; 05-11-2020 at 08:07 PM.. Reason: fixed typo
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