Howdy All;
Mythbusters did a project on this back in 06,07 or somewhere in that time frame...
Did the check with tailgate up,down with a cap and without, with a flat cover .....
best mileage they got was with tailgat in up position.
What they found was the air comes over the cab and hits the tailgate,
which in turn pushes the air forward to the back of the cab (ever open the sliding
window with a bunch of leaves in the back???), the air rises then rolls to the back
creating sort of a 'pillow' the new air goes over the cab across the 'pillow' then
back behind the truck........
hankaye
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Striving for a less complicated life since 1949 ...
Home: 2008 Cougar 278 RKS
T.V.: 2004 F-250 4X4, Level III BulletProofed , Detroit Tru-Track Differential (915A550)
Dog: 2006 Border Collie (Rascal) aka Maximum fur dispersal unit. (08/04/2006 - 12/16/2017) RIP.