I remember a while back (a few years, I think), this topic had come up.
Someone had suggested installing a device that would take the stagnant
air from the front of the van and direct it around the corners.
Also suggested was some sort of flap around the sides of the van that
would almost touch the ground, like those old f1 cars.

~enough of the contribution...  on a topic similar to this, where
would be the best place to pick up air for the engine?  I remember
something about boundary layers forming in front of the side air
pickups at speed (above 70mph). What about pulling air from underneath
(properly filtered before the engine, of course), or from a NACA duct
on the back 1/3 of the van side?

Sudhir

On 7/30/07, John Reddick <svyolo@yahoo.com> wrote:
> I saw some pics from a wind tunnel test on Vanagons.  The stock passenger
> van is .44, the US spec Westy is .50.  I am currently driving a Westy with a
> modified "aero" front end for the Westy top.  It is getting better mileage,
> but due to adverse traffic/winds, I could nail down good numbers.  It is
> definitely getting somewhere between 5-10% better mpg.
>    The Porsche 928 is a horrible example of aerodynamics, despite its sleek
> look.  Its Cd was similar to a Vanagons when it first came out, but I
> believe they tweeked it in the mid 80's so it was mid/low .30s.
>     Westy's sold in Europe had a bunch of variants on the top design.  One
> common one was the same rear as the US model, but a sleeker front.  That is
> basically what I built for the front of my Westy, although the first one is
> far from beautiful.
>
>     John
>