i personally like to drive with my tailgate down. they say that it saves you up to 7% mpg, not sure if its completely true, but i have noticed a bit of a diffrence. What are your thoughts on this and how do you drive, up or down?

 

Driving around town I drive with it up, long trips I will lower it untill I get my bed cover.

 

I hope you like wasting gas cuz driving with your tailgate down, especially on the highway, gives you worse gas mileage. Proven fact with a number of different experiments and tests. Search through the previous postings. This has been dicussed before and there are links to back it up. Mythbusters also did a show on this too and came up the with same conculsion that with the tailgate down you get worse gas mileage. Hope this helps.

 

I didn't think people worried about mpg when buying a full size truck w/ an 8 cyl engine.

 

The TV show "MYTHBUSTERS" on the Discovery Channel did an episode on this recently.(episode 43) They tested 2 identical Ford Trucks with driving one with the gate open and the other gate closed. They got worse gas mileage with the truck with the gate open. The reasoning was after doing air tests that the truck is designed to allow air to pass over the top of the truck and over the back end of the truck. By having the gate open it allow the air to bounce around and actually push down on the tailgate and bed thus causing more drag. It was really interesting and not what you would expect. Check it out http://www.discoverychannel.com.au/m...rs/index.shtml

 

More evidence that it is better to leave the tailgate up. WingViper and I are both Aerospace Engineers. We have a buddy who actually built a CFD (computational fluid dynamics) model of his 04 Dakota. He ran a highway cruise speed simulation with the model that showed the best aerodynamics are with a full bed cap, the next best are with a tonneau cover, next was tailgate up, then tailgate down, and the worst aerodynamics were when you use an "air gate". (which ironically enough are marketed as better for gas mileage than regular tail gates)

What happens with the tailgate up is that a small portion of the air spilling over the cab will form a swirling vortex in the bed with the air eventually spilling out over the sides. The majority of the air spilling over the top of the cab will bounce off this vortex. With the tailgate down all of the air wants to flow all the way down into the bed and out the back over the lowered tailgate. This creates more severe separtion of flow along the back wall of the cab and in layman's terms would be described as creating more negative pressure or "suction" so to speak than you get with the tailgate down. I believe it also creates a little more down force near the back of the bed.

Unless you get some kind of bed cover leave the tailgate up.

 

you would think you would get better gas milage with the gate down, thats odd. Thanks for the input guys/gals. Ill probally still drive with it down, can see better when backing up, i seem to back up alot. heh.

 

The tailgate also provides structural function to the bed rails. If you drive long enough with it down, you'll notice the sides of the bed will be slightly off. Usually, you see these on older vehicles. But one of my friends had an 01 Ram. Put a tonneau cover on it, then took it off along with the tailgate. Well, a year later when he went to reinstall the tonneau cover, it didn't sit right because the structural integrity of the bed was comprised with no tailgate.

 

Yeah man thats what I was going to say, go Mythbusters! What an awesome show lol

 

I never drive anywhere with the tailgate dwn, Ive seen too many bent up. Very expensive to replace.