The blend of gas most likely explains most of the increase in fuel efficiency.

I plan to get a Bakflip F1 for my '12 SCREW to protect the bed first and foremost.

 

Thanks MrEvil,
that is about what I have been seeing in test runs with my homemade experimental tonneau cover: I have been getting results that show anywhere from 0 to 1.0 mpg improvement when I have the cover mounted on the truck, depending on the cruising speed during the test.

I am looking at getting a BAK G2 cover, for the weather and "prying eyes" security issues. I like the hard suface and the flush mounting.

But I really wanted to try to develop a good answer for the mpg question as well. I have come to a conclusion that Ford may have, in the 2009-2012 models at least, sufficiently modified the shape of the truck cab so that cruising aerodynamics form even more of a sort of "air pillow" in the open truck bed, than in earlier trucks. In a lot of situations, the addition of a tonneau cover to these latest F-150 models might just not significantly improve much on the qualities of that built-in "dead air" space.

 

Yessir. With that 1MPG increase, I'm saving around $300 a year. So not only has the cover paid for itself, it is saving me money everytime I drive it.

 

I think it's safe to say he was joking...

 

The Anechoic chamber that I helped build at Eastern Michigan University shields out all microwaves, radio waves and all other outside interference. The exterior walls are 2mm zinc coated mild steel then a layer of 3/4" OSB, then another layer of zinc coated steel.

Built for testing antenni and precisely measuring radio wave deflection. All instruments for measuring are placed inside the chamber to prevent any electrical or wavelength interference, so very precise measurements can be made without distortion.

All the computers in the US Pentagon are housed inside Anechoic Chambers that shields from outside interference.

Guess I shoulda said 'Shielded Anechoic Chamber'.

 

First, @Exponentialpi - the blend was still 10% ethanol, and I filled up at the same stations as I have on all my trips there, so I doubt that's it. I think it's the extra couple thousand miles I've put on the truck since then, with the 1mpg the others are talking about in regards to having a tonneau cover on.

@Nimrod - somewhere on Ford's web site, they have videos showing how the back of the cab is designed to direct airflow to the top of the tailgate.

-John

 

Winter gas will give you worse mpg....just sayin

 

Yeah, we're still running 10% ethanol though, so it *should* be the same gas I got in winter.

-John

 

Around 1:12...

 

Thanks Silverfish - that's the video I was talking about earlier.

-John

 

I read an article a few years ago in a magazine , Truckin I believe, about teh pick up CART was using for a pace truck. They did bunch of wind tunnel and real world testing on different configurations. They ended up with Tonno that covered approximately teh rear two thirds of teh bed, with the front third open. This resulted in the lowest CD for the turck, Chevrolet ?, tested. They also stated that lengthening, or shortening the cover by a few inches made a huge difference in drag.
Looks like it might have had to do with seats as well.

http://rumors.automobilemag.com/cham...es-134522.html

 

No, it's not. Areas with 10% ethanol mandate still have separate winter and summer blends.

 

OK, thanks for the heads up.

-John

 

I'm just puzzled why: a) you use the word "confirmed" as if your plywood contraption along with the trip computer outweighs all studies done by anyone to date, and b) why is doesn't say "confirmed, tonneau covers improve mileage more or less about what has been claimed by most people all along". I opened the thread expecting to see a study that showed the tonneau to make MPG worse.

 

I could have told you that just from growing up in the 70's. Those who were at the back of the truck bed were blown all over. Those at the front we nice and shielded. The wind really started dying down around the wheel wells, but the sides of the bed were still well blown.