Which is more efficient, tailgate up or down?

[ANTAUS]

http://www.autoblog.com/2014/08/26/ford-f-150-tailgate-up-down-mpg-video/

[lquidspine]

Mythbusters has already done this, the answer is tailgate up; with the tailgate up it creates a circular wind pattern within the box which in turn allows air coming from the front of the truck to pass over the bed, with the tailgate down it creates a downward push as air passes the cab and pushes down on the back of the bed.

 

If I remember correctly they used F-150's during their testing.

 

Finding: BUSTED

Explanation: If you drive a pickup, common sense might lead you to think that opening the tailgate on the road is the more fuel efficient way to go. In fact, the idea that tailgates block airflow and increase drag became widely circulated, and some truck owners intentionally drive with the tailgates down to ease up on gas consumption.

But when MythBusters Jamie Hyneman and Adam Savage drove identical trucks under the same conditions across the desert — one with the tailgate up and the other with it down — Jamie's tailgate-closed pickup outlasted Adam's by more than 30 miles (48 kilometers).

Closing the tailgate actually improves fuel efficiency because it creates a type of airflow called a separated bubble within the bed of the truck. As wind rushes over the moving truck, that bubble of slow-moving air deflects it over the raised tailgate. By guiding surrounding air over and across the bed of the truck, that vortex effect prevents added drag.

However, driving with the tailgate open eliminates the bubble effect, pulling the air toward the truck bed and creating more drag rather than deflecting the wind. Some gas-conscious pickup drivers still swear by leaving their tailgates open, but science sides with leaving it up.

 

 

http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/driving-tailgate-fuel-consumption.htm

[goinbroke2]

Mythbusters is full of crap on so many things. Personally I've done back to back testing over periods of weeks with various trucks I've owned over the years. Basically it depends on speed and hp avail. My 93 7.3 4 door with 8ft box, made no difference up or down. My 81 f-350 8ft box with a 300/4spd went from 21 to 25mpg with tailgate down. repeated this many times. 81 f-100 with 300/3spd went from 19 to 21mpg with down. 85 f-250 supercab with 6.9/4spd made no difference up or down.

 

Another note, when towing my mustang on a car dolly,(and a cap on the truck) there was a 3 mpg difference towing it backwards as opposed to towing it forwards. With the slide in camper it went to 5mpg difference.

 

Since trucks are my daily drivers and I'm annal about things like that I've done the testing over and over, not a one time test with one vehicle on one day in one weather situation. Mythbusters are so full of shit if they are talking about something you know. If you have no idea what they're talking about it makes great "entertainment".

One quick example is how they "proved" you can't jump a car and then drive away....then after "busting" a 100ft jump, (which they let the car stuff in nose first because they didn't balance it) they show the world record holder who jumped 300ft and then drove off the course! Veh can't jump 30-50ft huh? Ever see stadium racing??

It's entertainment, not real proof of anything. They blew a moonshine still up by plugging the output, having a spark available and basically setting the stage to prove that a moonshine still will blow up and kill people....even though they couldn't do it until they made assumptions they anybody running a still must be stupid/backwoods/wears bib overalls and would "probably do this and this" Yeah whatever, idiots.

 

Bottom line, NO TRUCK IS THE EXACT SAME so test it yourself and see if it works. Don't drive 20miles to grandma's house and then 20miles home and say "yup it was better going there with the tailgate up"(or down) Do your own test on your own truck where YOU drive and how YOU drive. Then come tell us what you found.

[30 OTT 6]

With the tailgate question answered I now wonder how tonneau covers (hard or soft) effect pickup fuel economy?

[30 OTT 6]

With the tailgate question answered I now wonder how tonneau covers (hard or soft) effect pickup fuel economy?

Apparently it doesn't have much effect on fuel economy but at least it doesn't reduce it.

[fordmantpw]

With the tailgate question answered I now wonder how tonneau covers (hard or soft) effect pickup fuel economy?

 

The video in the original link mentioned that fuel economy is better with a tonneau. I typically see about 1 MPG better with my tonneau than without. I have run a tonneau on every truck I have owned.

[SoonerLS]

With the tailgate question answered I now wonder how tonneau covers (hard or soft) effect pickup fuel economy?

Back in '86 or '87, Consumer Reports said that they were surprised to find that a tonneau cover actually decreased the fuel economy on the F150; apparently Ford had put some effort into the box design. It was, IIRC, a slight, but measurable, decrease.

 

On my '13 F150, I can tell you that adding a toolbox didn't noticeably affect my mileage. Its effect on my ability to see the contents of the bed in the rear view mirror is another story entirely...

Edited August 27, 2014 by SoonerLS

[fordmantpw]

I CAN attest to the fact that hooking a 9500 lb fifth wheel to the back of my truck DOES decrease fuel economy noticeably. Or maybe that's just because I have to roll up to tonneau to hook it up.

[RangerM]

With the tailgate question answered I now wonder how tonneau covers (hard or soft) effect pickup fuel economy?

Soft might increase mpg due to air flow, Hard might hurt mpg due to weight.

 

My $0.02.