Tailgate UP to Save Gas!

dbc · 05-15-2007, 05:47 AM

This one sure changes the common perception! For years I have always beleived having the tailgate down saved gas. Made sense when you think about it. Boy is that wrong....Last night on the TV Show Mythbusters they took 2 identical trucks, (Furds) and drove them for 400 miles; one with tailgate up and the other with it down. The truck with the tailgate UP went 30some odd miles further on a tank of gas!

Turns out there is a vortex created behind the cab with the tailgate up that causes the air to "bounce" or ride over the tailgate. With the tailgate down the air pushes down on the tailgate causing drag. They used a water tunnel to demonstrate and it sure showed it clearly.

What about all the sales pitches for a "lid" to save $$'s?

**Blackbeauty** · 05-15-2007, 05:56 AM

Yup. this isn't your Grandfather's Oldsmobile anymore.... Aerodynamics of rolling refrigerators has changed. Now, let's work on testing with tonneau covers......

Wiscdave · 05-15-2007, 05:57 AM

Yeah, I don't know...those guys are stunt junkies not chemists or engineers. You could take 2 titans and put the same amount of gas in each and do the same thing and I bet you'd get different results. Alignment, air pressure, ecu settings, waxed or unwaxed - and various other variables to prove this theory. I always used to drive with tailgate down, I thought it helped. I know have a cover and use that and truely believe that works. I would say given the crappy mpg on our trucks anyway...up down about a wash.

**Blackbeauty** · 05-15-2007, 06:00 AM

Quote:

Originally Posted by Wiscdave

Yeah, I don't know...those guys are stunt junkies not chemists or engineers. You could take 2 titans and put the same amount of gas in each and do the same thing and I bet you'd get different results. Alignment, air pressure, ecu settings, waxed or unwaxed - and various other variables to prove this theory. I always used to drive with tailgate down, I thought it helped. I know have a cover and use that and truely believe that works. I would say given the crappy mpg on our trucks anyway...up down about a wash.

A little research online could do you some good WD. There have been many tests, scientific and otherwise to prove this theory. Colleges and Universities all over the country have taken a crack at it with similar results. It makes a difference. You're never going to get 40 MPG, but you'll get a slight increase in MPG overall with similar driving techniques. A heavy right foot is the biggest MPG drain. Period.

dbc · 05-15-2007, 06:06 AM

They may be stunt junkies but they make every effort to keep things constant. As BBeauty says check out the online reseaarch; it's all there to prove it. See the following link for infor from the National REsearch Council of Canada.

nrc-cnrc.gc.ca/highlights/2007/0705uplands_e.html - add in the w w w in the begginging.

Nuke · 05-15-2007, 07:15 AM

Quote:

Originally Posted by dbc

They may be stunt junkies but they make every effort to keep things constant. As BBeauty says check out the online reseaarch; it's all there to prove it. See the following link for infor from the National REsearch Council of Canada.

nrc-cnrc.gc.ca/highlights/2007/0705uplands_e.html - add in the w w w in the begginging.

Good article. At the bottom of the page,
"3 – Put a tonneau cover on your pickup truck's bed. The cover is the best way to reduce drag and save fuel."

Wiscdave · 05-15-2007, 07:30 AM

I think that the brushguard on mine kills MPG. If I have the atv is in the back with the tailgate down its a little worse because of the drag there. Hey, I do keep it up now cause of this topic being discussed a couple years ago on here. But I don't believe everything I read or see on tv...

Gunner22 · 05-15-2007, 07:47 AM

Quote:

Originally Posted by Nuke

Good article. At the bottom of the page,
"3 – Put a tonneau cover on your pickup truck's bed. The cover is the best way to reduce drag and save fuel."

I can vouch for that. Last summer I was never getting over 17 mpg on the hwy. Bought a tonneau cover and I got 18 on average for the rest of the "good fuel/ warm temp" driving season. My tonneau and amsoil air filter have picked me up almost 2 mpg on average since last summer (this was after I had at least 12,000 miles on the truck so I'm thinking that eliminates any break-in gains)

BigA · 05-15-2007, 08:16 AM

Yea, thier have been many tests over the years that prove that driving with the tailgate up saves gas, all the car magazines have reported this, and now Myth Busters has too. Tonneau covers are the best to save on gas, also putting on a bug shield will lower your mileage by one or two miles per gallon at highway speeds.

**sledge** · 05-15-2007, 08:23 AM

here we go again.

Don't forget to change your conooter vavle every 10K.

**gadget74** · 05-15-2007, 08:37 AM

Quote:

Originally Posted by Wiscdave

I think that the brushguard on mine kills MPG. If I have the atv is in the back with the tailgate down its a little worse because of the drag there. Hey, I do keep it up now cause of this topic being discussed a couple years ago on here. But I don't believe everything I read or see on tv...

so how do you like that brushguard?

EVO8 · 05-15-2007, 10:25 AM

Interesting information, I guess I won't be buying a cover. A couple of friends that own dodges took their tail gate off because they believed that it would save gas. I'll have to go laugh at them for making their gas mileage even worse.

HiggySTL · 05-15-2007, 10:26 AM

I wathced that same episode of Mythbusters too. In fact, they did a follow on show (backed by popular demand), and this time they tested the trucks with; tailgate up, tailgate down, tailgate off and lastly with a tonneau cover. Once again, their test shown tailgate up resulted in the best mpg, with the tonneau cover being a close second. I found that very interesting. I know many will diagree with their findings, but I am just the messanger.

Wiscdave · 05-15-2007, 01:11 PM

Quote:

Originally Posted by EVO8

Interesting information, I guess I won't be buying a cover. A couple of friends that own dodges took their tail gate off because they believed that it would save gas. I'll have to go laugh at them for making their gas mileage even worse.

Yeah but the truck is faster, less weight. At the track take off spare and tailgate, take out therear seat too - gona get you a .01-.02 off your 1/4 times.

You guys can laugh, but I got the best mpg out of my truck stock - amsoil -with the tornado - 400-420 miles to tank all day, everyday. T hen I sold the tornado, put on the banks and CAI...340 miles to tank. Man was it fast.

**DeadRiver** · 05-15-2007, 02:31 PM

Quote:

Originally Posted by sledge

here we go again.

Don't forget to change your conooter vavle every 10K.

i thought it was spelled "kanooter" could be a branding thing though

i also watched the mythbusters, they used:

tailgate up (best result because during a vehicles aerodynamic testing this is how the test all the drag coefficents)
tailgate down
tailgate made of mesh
tonue cover

they also did another study with the windows up vs. windows down. i think they did better with the windows up and a.c. on.