Gas Mileage and Tailgates

I've been looking to see if there is a better way to keep my tailgate position; open, closed, off, netting, etc, in relationship to gas mileage.

I looked into this a while ago and found conflicting information and studies. So far, my memory tells me the best gas mileage to the worst is this:

- Shell (well fitted and lightweight)
http://www.ehow.com/facts_7533243_effect-tailgate-cover-gas-mileage.html
- Tailgate down
- Tailgate up
- Net tailgate
- Tailgate off

Can anyone provide evidence (contrary or supporting or personal) of this?

Tonneau cover better. Tailgate off or net tailgate worse.
http://www.ehow.com/facts_7533243_effect-tailgate-cover-gas-mileage.html

 

Anyone?

 

I believe mythbusters tested this and concluded that you get better MPG's with the tailgate closed. it creates a swirling effect in the bed an helps push your truck forward.

 

http://www.youtube.com/watch?v=r3aqHbD-O9E

 

I have a tonneau but don't think it does much for mileage. I usually get the rated highway mpg around town. The biggest factor in mpg for me is how hard i press on the gas pedal.

 

X2 whipper, I'm always afraid some asshat is going to hit it with the way some people tailgate, No pun intended!