Mythbusters claim on their site that driving a pickup (looks like a F250 or 350 in the pic) with the tailgate up results in better mpg than with it down/open.

This myth is not busted. What kind of scientific methodology dictates that you use two different trucks with two different drivers, and one with the tailgate up and the other down. Way too many variables. Just the fact that you're driving two different trucks, much less the fact that you have two different drivers!

I have a new Ford F150 that I drove for two weeks (crew cab, 4x4, 6 speed auto, 3.5L) with the tailgate up while waiting for my bed extender to come in. I got 17.5mpg with the tailgate up (hwy and city, 104 mile roundtrip daily commute). Once I installed the bed extender and started leaving the tailgate down with the bed extender folded out I consistently get 18.5mpg. I would be happy to have the mythbusters challenge my test results as they are easily repeatable. One truck, one driver, tailgate open, and then tailgate closed, over a combination hwy and city course.

And while we're on it, I have been getting even better mileage improvements doing the same thing with my 2002 Ford Sport Trac (2wd) since it was new. The difference between tailgate up and tailgate down is 2mpg (it also has a bed extender).

S.

 

I reject your reality and substitute with my own

 

I thought the same thing. They can't use two different trucks! WTF were they thinking? Also, on the episode where they tried to rip the rear end out of a police car like they did on American Graffiti. They used a completely different car than the one on the movie. Dumb!

 

The theory behind tailgate up and down I'm sure will always have some argument to it. Engineers designs the bed of vehicle bed to create air pocket and allow for aerodynamics. Putting your tailgate down eliminates air pocket and creates drag. Like I said this is just the theory of there design.

 

C'mon guys, it's a TV show meant to entertain people! Information on that show should be taken with a grain of salt lol

 

The episode I saw, had 2 identical 04-08 F150's. Identical distance, speed, and amount of gas in each tank. Only diference was tailgate up on one, and down on the other.

 

This^

There was a video on 09+ F150 aerodynamics and they talked about things just like this purposefully designed to be aerodynamic. That's what the lip on the top of the tailgate is for too.

 

And what were the results?

 

That tailgate up is more efficient. I saw it too

 

If I remember right, the one with the gate up, went 30 miles further than the one with the gate down.