Frank Marcus shared an interesting ( to me ) tidbit in the May, 2023 edition of the above, page 76.
They have a long-term KIA Carnival van, that Markus has done 700-mile road trips in.
On one trip, a 500-pound capacity, receiver-hitch mounted,24" by 60" REESE Explore ProSeries cargo carrier was added.
Mpg for the 700-mile trip registered 24.7-mpg with, compared to 23.6-mpg without.
Marcus isn't ready to attribute the carrier to the fuel economy difference, but it's information.
As an aside, back-soiling of the van's backlight was significantly reduced during rain events.
Hucho's schematic representations of time-averaged squareback wake flow provide some insight into unobstructed wake turbulence transport of liquid water onto a squareback base.
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If one imagines NASA's, 1977, Cd 0.238, 'Project Shoebox' boat tail slipped 'over' that cargo carrier, it makes for an interesting thought experiment.
Something not lost on the creators of the ' 300-mpg ' AirShip L1 RV travel trailer.
