Gas milage


Do pick up trucks get better milage with the tailgate up or down? Or does it make a difference?


The Mythbusters of Discovery TV busted this one a couple or three years ago. Apparently it makes no appreciable difference whether your tailgate is up or down. Leaving it down will cause more severe damage to both vehicles in a rear end accident.


The tailgate also supports the sides of the truck bed in the up position.


I thought they found there was a slight decrease in mileage with the tailgate down. Or maybe that was someone else that found that.


i thought the same results about the tailgate UP made less turbulence and had a more smooth airflow off the back of the truck?

but then again i don’t believe in hydrogen for gas either, so who knows!

but without *****'s i can’t get a good read on your advice!


The only reasonable test I have seen was done by Mythbusters and as I recall up was best. It created a kind of rolling effect for the wind in the bed of the truck giving it a clean air flow over the cab then over that rolling closed circuit of air in the bed an then behind the truck. Opening the tailgate messed it all up.


The Mythbusters’ testing showed no difference with the tailgate up or down, but they also tested a cargo net in place of the tailgate. Much to everyone’s surprise, the cargo net gave a slight improvement in fuel economy.


You remember correctly. Tailgate up is beter.



For some, the damage to the person who rear ended you would be worth it.


Gate up. I read some years ago that with the gate up an “invisible bubble” of air occupies the bed so the air comes off the cab and flows over the top of the bed as if you had a hard bed cover in place. There is a technical term for this but the name eludes me now.


Consumer Reports tested this years ago with different sizes and types of pickups. The results were mixed. Some got very slight improvements with the gate down, some were slightly better with the gate up, some showed no difference. All differences were extremely marginal as to be inconclusive.

In the '80s I drove my Toyota pickup 103 miles, mostly highway, each way every day to work for one year. 206 miles a day. I tested this on my truck. I found absolutely no difference.


I accidentally drove off in my pickup with a plastic bag full of packing peanuts once, and though they all flew around wildly in the bed, not a one of them flew out. I think this confirms the “bubble of air” in the bed. IIRC, the mythbusters’ results were that the truck with the gate up went an extra 30 miles or so on the tank.


To get good mileage out of a truck, buy one with a 4 cyl. engine and a stick shift…

Instead of worrying about the tailgate, slow down 10 mph. That will make a MUCH bigger difference…And remember, NOTHING destroys fuel mileage like acceleration does.