<VV> Tailgates

[James P. Rice]

All:  There was article in some magazine I then read many years ago about
the tailgate up or down.  The mileage improvement was there, but the also
instrumented the underbody air flow and pressures.  Found the tailgate down
produced a fair amount of aero-lift at the rear of the truck.  Someplace
where I think most of us think you don't want aero lift.

There are better solutions.  Cheap one: when I had a '03 GMC Sonoma (SLS,
V-6, 5-sp, ZQ8 suspension, extended cab, red) I cut down a 4x8 piece of ply
wood to fit the bed liner.  It was angled low into the front bottom of the
bed, cutouts for wheel wells and rested on the edge of the tail gate.  I got
about 2 more mpg at 70mph with it.  In the winter, watching the snow swirl
was a visual lesson in my truck's aerodynamics.

Historically Yours,
			James Rice


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Message: 2
Date: Sun, 21 Aug 2011 12:11:43 -0500
From: Joel McGregor <joelsplace at earthling.net>
Subject: Re: <VV> Better mileage with the top down. & engine temps
To: "virtualvairs at corvair.org" <virtualvairs at corvair.org>

My '73 El Camino used to gain 5mph top speed with the tailgate down.  It
would run 110mph up and 115mph with it down.  I would think a tailgate would
make less difference the faster you went.  Wouldn't the air flow over the
top fall off quicker and hit the tail gate more at lower speeds?  Just a
thought.

Corvair content:  Do engines cool better in convertibles with the top down?
I would think that the air intake would be less of a low pressure area with
the top down.  Mine runs around 400-425 on the stock gauge running at 60-70
mph.  Is that normal?  (only one I've had with a working guage).

Joel