I have a bet with a coworker. I am looking for anyone with concrete proof that having the tailgate down is a myth. I have a flat fiberglass tonneau cover on my truck and i had it off for a month and did not notice any difference in mpg with or without it but he swears he gets 2 to 4 more mpg with the gate down. does anyone have any proof one way or the other. by the way the bet is 50.00.thank you all.

 

I can't really tell much of a difference with mine personally. I even had a camper shell on for about a year with similar mileage. I did recall seeing this on mythbusters a while back though, here is their brief write up:
Tailgate Up or Down Revisited: Mesh tailgate, hardcover, tailgate removal

See: Tailgate Up or Down

For the original myth they did a driving test and a water vortex test, both of which showed that you save more gas with the tailgate up. Their viewers suggested that they test three new conditions:

* Hardroof cover over pickup bed
* Mesh tailgate
* Remove the entire tailgate

They had a much simpler test setup this time. They had an electronic flowmeter hooked into fuel line of Jamie's pickup. Adam: "For anyone out there that wants to e-mail telling me that we screwed up this test, we have already calibrated this thing, to this car. So it's going to be perfect!" They drove the pickup truck up and down the stretch of 101 around Candlestick and the Cow Palace.

* Tailgate down: 5.2 gallons/hr @ 55mph. 1.2 gallons/hr @ 25.
* Tailgate up: 5.0 gallons/hr @ 55mph. No reading for 25mph given, but tailgate up was once again confirmed as more efficient.
* Hardcover over pickup bed: 5.0 gallons/hr @ 55mph. 1.2 gallons/hr @25mph
* Tailgate mesh: 5% more efficient
* Tailgate removed: about the same as tailgate up and hardcover

Mesh was most efficient by 5%

 

it is a myth... they did do this on mythbusters

 

agreed, mythbysters proved it wrong

**BUT** - some people swear by their own ways and test. if they get better mpg's, let them.

 

I think its stupid to drive with it down because the one time you back into something the money saved on gas wont make up for a tweaked tailgate!

 

It's dependent on the styling of your vehical. If it is lifted with big tires and the works, your already suffering, and i doubt you'll get a difference. If you have a choped and lowered truck, there will be a difference.

Also, for some reason, this myth changes between different manufactures. dodge and chevy actually get considerably worse mileage with the gate down, ford is slightly less negligable. The honda ridgeline gets better mileage. Note this is all on similarly sized trucks (DODGE 1500, CHEVY 1500, FORD F-150, HONDA RIDGELINE). All with about a 5.0L V8 and 4wd.

I'm not sure about the ranger and how it is affected, but before you can put money down, you can only have on variable that changes. a lifted truck with the gate up, will get almost the same mileage as it does with the gate down, but a stock truck, or a modified low slung truck will have a noticable difference.

 

I've never measured with the tailgate down. Before he put the cap on his Dodge diesel, my uncle used to get about 2-3 mpg with the tailgate down or off.

If I was your co-worker though, I wouldn't pay up until I saw much more conclusive evidence than guys posting stuff on the internet...

 

Collect your money..sorta

http://www.popularmechanics.com/auto...11.html?page=5

Dave

 

There have been a number of studies by a variety of organizations/groups and they all busted the tailgate down gas saver myth. I have seen about a half dozen over the years with various test methods.

 

I just read an article in Truck Trend (I think) that showed a tailgate at 45 degrees (half way between open and closed) was the best way. The diesel truck they tested went 12 mph faster on the top end with the tailgate at 45 degrees. Interesting ....

 

My coworker and I have called a truce. I showed him all the info on here and the Myth Busters story and we have decided that there just is no concrete evidence. There just isnt much u can do to the 3.slo engine. I guess if I want horsepower i will just have to buy a cobra or Roush Stang vroom vroom.

 

How are you suppose to keep a tailgate at 45 deg?

 

I'd use a protractor.

 

um... yeah. where did you read this? or did you see this in a movie from hollywood? i'd like a link from a CREDIBLE source please... thanks!

 

After thinking on it a while, I remember some time ago I drove from Lancaster, PA to Milwaukee, WI. I had an '82 150 standard cab 4x4 with a 302 that I had built in it. This was in the early 90's.
Thinking this was the perfect opportunity to take advantage of increased mileage from traveling w/out a tailgate, I took it off and stowed it flat in the bed. I was anticipating a measurable improvement in economy over that long distance at highway speeds, but I distinctly remembering having to stop for fuel more frequently than I had calculated.
I don't have those old notes any more, but I remeber distinctly having experienced a genuine decrease in mileage.