wind drag/weight conversion

Every vehicle mfg. has some statement or other about 'Frontal Area' (Typically 60 Sq.Ft.)


FRONTAL AREA
The total area in square feet that a moving vehicle and trailer exposes to air resistance.
Exceeding these limitations may significantly reduce the performance of your towing vehicle.
Selecting a trailer with a low-drag, rounded front design will help optimize performance and fuel economy.

It would be (fun?) to see some sort of math on it.

I know I get 19 mpg on my pick up, but had to move mom in law and put side boards on and in front the plywood stuck up 4 feet and my mpg went down to 12. And with her stuff loaded only dropped mpg another 1 1/2, so wind much more important than weight of load.

Thats about what I have come up with on the lighter side, to upwards of 2000 on the heavier side. An airstream will be on lighter side. A ft with an aluminum corrugated front, fairly straight up and down will be in the heavier side.

A 15k rig with 70 ft of frontal needs about 105 up to go 60 mph. 90 ft will need 135 or so. Any of these figures can vary upwards of 30% depending upon the aerodynamics of the setup.

Marty

I've heard metrics like that but there are several variables like the slope of the front of the trailer, etc. Different trucks will create different aerodynamics on the trailer too. I'm sure there is a general rule of thumb but could not tell you what it is.

Do you get to subtract thousands of pounds for a tail wind?