Yeah, no variability there either...

One truck, one driver (or better, automated controls), tailgate open then tailgate closed... ON A CLOSED COURSE with the same weather conditions. Then you get closer to an objective analysis.

 

Haha you quote wh0re

 

This topic used to be an obsession of mine with my old Ranger. I used to keep a spreadsheet of my MPG, and would alternate between gate down and gate up. I generally found my MPG was 1-1.3 MPG higher with the gate up.

But this was a Ranger.

 

A few years ago they did a test with two Ford Explorers to which was better, a/c on or windows down, to save gas. I think it was a tie, can't remember. But I'll take the cold a/c over hot air through the windows anyday.

 

The results would likely vary depending on bed length too. After all the truck shape is the same other than the bed length, so I would expect different results between 5.5', 6.5' and 8' beds.

 

It could also vary with which cab it has, 4x4 or 4x2 and gear ratios. I'm pretty sure they took the pickup that was Ford's best selling and used that

 

I have heard that with the tailgate down that the wind would cause the rear of the truck to have a constant weight on it and get worse MPG. But if you took the tailgate off it would in prove MPG because it let more wind to escape the rear of the truck. Or something like that.

 

850, So right and he doesn't even know it.

http://www.nrc-cnrc.gc.ca/eng/news/nrc/2007/05/07/tailgate-down-myth.html

Unbiased wind tunnel testing of the last body style F150 by our friends to the north (see they dont spend all of their time at Tim Hortons and harvesting maple syrup) found the shorter the bed the worse the mileage when the tailgate is left down and ALL pickups lost fuel economy with the tailgate down. Also mesh tailgates were WORSE than even leaving the tailgate down for creating air disturbance and drag.

 

When the tailgate is up, air coming over the roof drops down hitting the tailgate sending it forward and creating a spinning ball of air which acts like a cap in the bed.
You've all seen what leaves do while driving.....

 

Don’t forget #3 on the northerners' list of pickup truck tips: get a tonneau.