On Apr 9, 2:19*pm, Adam wrote:
More trailer-talk....

I have a Minden-Fab / Scheder-style trailer and tow with a 200hp V6
station wagon. The front "barndoor" of the trailer is about 1.5 to 2
feet higher than the roofline of the car. The whole setup feels draggy
on the road. 65 mph is about the limit before I feel like I am abusing
things. I get about 17 mpg with the trailer, 26mpg without. I plan on
a 3000 mile round trip this summer and with gas where it is, a few
more mpg would be nice.

I was wondering if it would be worth fitting a deflector to my luggage
rails near the back of the wagon to reduce the drag and increase my
mpg a few points (and my L/D would also go up too!).

I will can fabricate something from stainless sheetmetal that would
mount to my Thule rack. Any tips or guidelines on the form of such a
deflector are appreciated. Or is this a bad idea?

Thanks,
Adam

In Hoerner's book, Fluid Dynamic Drag, he shows that the drag
coefficient of a simple box shape can be reduced by about 40% (from .
86 to .46) by rounding all the corners with a radius of about .10
times the sides of the flat front and rea faces of the box.

A deflector at the front would be good. I think the back end is at
least as important, if not more so. Why? I have pulled a variety of
trailer weights and shapes behind my 1990 chevy van. The one that
give me the lowest mileage is the one with the biggest flat plate at
the rear. And in pulling some of the nice, low profile clamshell
trailers, I have actually gotten better gas mileage than normal.

I started a plan for fairings, etc, when I was doing all my trailer
pulling with a Camaro. Now that I have the van, I am less
interested. But, I still have things started, and templates for
making a fairing for the tail end of my "egg hauler" trailer. The
trailer has the cross section of an egg, about 6 feet tall and 4 feet
wide.

Try something, but keep this in mind. Even at $3.50 per gallon, and
going from 17 to 19 MPG,on a 3000 mile trip, this will only save you
about $65 in gas. So, you have got to make your fairings cheap or you
spend more than you will save.

Steve