I have fiberglass bedcover on mine and it help's a bit.I do need front air dam.Wasn't on truck when I got it.

 

It's funny you mentioned that. I just watched a Mythbusters episode where they revisited a previously busted myth about tailgate up/down fuel mileage. This time they did tailgate up, down, off, off with a net, and a bedcover. The best possible configuration was tailgate off with a net, just beating out a surprise tailgate up configuration.

Back on topic....

To just "assume" that because the factory bumper is shaped like a parachute it catches wind doesn't hold much water to me. Taking into consideration many tests done in wind tunnels with the tailgate myth, I'd like to see (just for chits and giggles) the airflow patterns under the truck. Based on what I have seen in similar vehicles, I personally think the front axle, trans mount crossmember, rear axle, and in some cases the spare tire location would cause so much turbulence in the flow that the rear bumper would have little to no influence at all.

I could be, and probably am wrong lol, but honestly, the only way I have improved gas mileage in my truck was......take the car instead

 

I would have never thought that.But I guess you take away the tailgate that's like 50 lbs? lol

 

Here's a better question, what kind of mileage do you get now? To help, I get about 12mpg with suburban driving to work and school about 30+ miles a day.

 

Got a fancy electric fan and Meziere pump already -- good part of why I'm currently getting 27-30mpg on summer blend fuel now (@55mph).

 

like i said in another post as it was told to me that "we are driving vehicles with the aerodynamics of a brick so dont expect too many mpgs"

 

wow.27-30 mpg is pretty dang impressive.
good job!

i keep reading this too.
this is what people who would rather not try doing anything, tell themselves.
imho,this is all the more reason we need to work harder to improve where we can.

 

It's really hard to get the best numbers consistently because of so many factors you can't control. You get your best results near the EPA test temperature of 68 degrees. Any kind of wind, including cross-winds, can complicate things. And there's humidity. Bumpy pavement. Hills. Winter vs summer fuel blend, percent ethanol, and more.<br /><br />This year I hope to experiment more with aerodynamics, as well as verifying that the cylinder output is as even as possible. Verifying that the compression is fairly even and figuring out a way to even out injector performance would be nice. The two upstream HEGOs have to deal with an entire bank each, and one cylinder partially out of whack can hurt you as the computer tries to fix things by adjusting the others.<br /><br />In the end, I want to have a vehicle that does really well with fuel economy, but that is immediately identified as a "pickup truck" by anyone looking at a picture of it.

 

I find it hard to believe a F-150 doing 27-30 mpg unless it had a diesel conversion. How did you measure them? Which mods does the truck have?.

 

You're right to be skeptical.<br /><br />The results were taken from repeated trips over a 105 mile course, on a fairly flat stretch of interstate mostly between Providence, RI and Cape Cod, MA (I-195).<br /><br />There are all sorts of reasons that people are honestly wrong about the fuel economy they report. A change of tire size (or differential) might overstate the distance traveled, and thereby the fuel economy.<br /><br />Many people don't know that their speedometer reads 1-3 MPH slow at highway speeds, and so they're not going as fast as they think.<br /><br />Some don't account for tailwinds or take credit for the effect of "drafting".<br /><br />I tried to label most of my mods in the picture, but probably the biggest single thing is driving the speed limit! When a vehicle has aerodynamics this poor, then the slower you go, the less aerodynamics matter.<br /><br />A number of things not listed include keeping the tires rock-hard at max-PSI all the time. My fuel economy REALLY sucked when I got the truck because both tanks leaked. Now I've got two complete new tanks and sending units.<br /><br />I've not done any new tests this year because of the winter / winter fuel, and I've not had much time to practice with the ScanGuage, which I hope will make my results more repeatable.<br /><br />Getting a handle on driver behavior is a big deal:<br /><br />100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com<br /><br />A lot of this stuff only works in "commuter" driving mode. When you're hauling a stack of ladders or the truck is "working" your mileage reflects it!