I'm with autobahn. The sail is a good idea. I always smile when I see this one. Our trucks are 7000lb bricks.
Some people swear by tonneau covers, cold air intakes, free flowing exhaust, chips, intake and exhaust headers.
Unfortunatley you'll find as many people who don't think these mods do much at all for mileage. Performance yes and even that is sometimes. I think you will probably have your foot in it more often killing the mileage benefits.
Funny...this exact same argument rages from time to time on the automotive board I came from. That one -- a sports car board -- never discusses mileage increase or decrease with these mods (well, almost never), but the debate runs rampant about actual gains.
Having chipped and modded four of these little roadsters, I know what the effects were, and that the naysayers almost always were folks who'd never done it, and never would, 'cuz they had heard...! Don't know a thing about modding these trucks yet, but will learn. And based on my previous experiences, I'll almost certainly spend the money on mods when they become available for my truck. However, NONE of them will be to increase mileage. (o;
I removed the converter and added a Flowmaster cat back kit and noticed 1 or 2 more mpg's here and there. I also added a Superchip... but have no idea whether it added to the mpg's tho. Sure added some power tho.
See that skinny pedal on the right? Don't push it so hard... Seriously, though, most of the mods that happen to increase gas milage (and slightly, at that) will take so long to pay for themselves that you're probably better off just sticking to what you have... But, I'm just a dirty diesel owner...
I'm surprised by these low numbers, but maybe my circumstances are unusual.
I have a seventy-six mile round trip commute with speeds ranging from 75 mph down to 55 mph in the morning and generally stop and go for half the commute in the evenings. Even so, my computer (I'm too lazy to put pencil to paper) says I average 14.1 mpg unloaded. Until I changed over to my 285 BFG's from the OEM Firestones last year, that number was closer to 14.7. If I put almost any kind of a load on it, then the numbers drop down to the 11-12 range.
I changed out the stock air filter with the K&N two years ago with no noticeable change in performance. Other than that, the truck is stock, SB, CC, 4x4 01 Platinum Edition. 93K+ miles and no complaints from this owner.
Yes a chip will increase your mileage some but for the price of the chip and the cost of the premium fuel you have to use with the chip and the fact you will have to "test" every so often to make sure the chip is working you might as well save your money. That being said a chip does give you firmer shifts, more horsepower, and more torque.
The above link is to a Four Wheeler mag article. If link doesn't work, just go to Four Wheeler mag site and look up the "Project M.P.G." articles. They did testing on aftermarket products like ones being discussed in this thread.
They give real stats on the results.
Just about any add-on does some good some where, but like mentioned, there is often a price to pay on some other performance issue. You must consider the give and take involved when you bolt-on any product.
Another factor not mentioned a lot, ROI (Return On Investment).
If you spend the bucks (for example) on a chip or exhaust system, or maybe both, how much are you going to spend? Reality now, that's cost of any and all parts involved plus installation.
Now compare that to possible countable gains in fuel mileage.
Are you going to 'make' enough money in increased mpg savings to pay for those parts?
Not saying it can't be done, but it's usually a multi year prospect.
I'm in an '04 Crew, LWB, 5.4, auto, 3.73 gears, and get 12.7 mpg on a very regular basis. Mostly in city and across town highway, almost always carrying a load or towing approx. 2000 lbs trailer and load.
The right foot's ability to bend forward at the ankle has the most profound difference in mpg. Not saying you have to drive like an inmate of a retirement home, but I had to scold myself after I first got my truck. Whoever said a 5.4 wasn't spunky? As much fun as it was, had to stop chirping the tires on take off.
Bottom line- Your driving habits/methods are the easiest and least costly 'add-ons' you can make for mpg reasons.
I eagerly search for any add-on that will really make a difference in mpg, but so far . . . . . . . . . . . . . nothing I've seen or heard of will make enough difference to pay for itself.
Tip- Don't believe a word in any ad, and only about a 10th of what someone tells you about their experience with an add-on. :-)