"Morgans" wrote in message
...

"Peter Dohm" wrote

It is not hard to believe at all--except for the proposition that either
trick (gate open or gate closed) works on all trucks at all speeds.

Trucks are not that different. Except for something like the old El
Camino, thy
are mostly boxes on wheels, to the wind.

Sure, they have a small styling curve here and there, but most of them are
square chopped off behind the cab, and have tailgates about the same
height.
--
Jim in NC

IMHO, they vary a great deal, and radically sloped windshields and extended
cabs both influence the size, intensity, and placement of the vortex. The
length of the cab will also influence the width of the vortex and crosswinds
will cause an offset.

OTOH, aerodynamic side mirrors (if available), or the presence or absence of
a front air dam, would probably make much more difference than the position
of the tail gate.

There are a lot of aerodynamic tricks, such as belly pans which can make a
huge difference, that just won't work for owners who really use their
trucks.

Peter