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Hello all,
I've read some post on mpg and saw some of you are getting 21 mpg. those of you that are getting 21mpg what is your set up? I'm currently getting 17 mpg on the hwy. with a 2005 f-150 xlt 4x4 with the 5.4 3v automatic trans. with the 3.55 gear no mods. thanks.
I get 19.2 to 19.4 when I go to Houston. That is on a lot of two lane highway, going through some small towns and driving 75 to 80. My tach reads 2000 rpms at 75. Supercrew, 5.4, 3.55 ratio, two people and lots of "stuff". I make the trip frequently and average this on the trip down. Coming home is more uphill and I usually average about 18.8 to 19.
I got 19.1mpg on the way from Gainesville to Selma. Mostly 4 lane highways at 65-70mph. My tach read around 2K. 2004 Screw FX4, 3" Leveling kit, 5.4L 3V, 3.73LS, one person and lots of hunting gear. That was the best I ever got.
My truck did it once on a 2 hour drive through country roads with rolling hills. Kwik Trip 87 gas, 60ish on cruse control, no wind and AC was broke (windows up). And yes… verified by hand because I didn’t believe it either.
Thats not the "TRUE" milage. Your PCM uses a mathematical formula (how much gas is used, injection timing, air temp. engine temp, speed, etc...) to give you a rough estimate of what your getting for milage. I don't remember the exact way it calculates the milage, but it's more of an educational guess then an exact science.
My FX4 doesn't do the fuel economy for me either. I just divide the number of miles driven by the number of gallons of fuel. I average around 15.5 in the city and, like I posted earlier, the best on the road is 19.1.
There are so many factors to look at when evaluating MPG.
What truck do you have (they all weigh different, and weight counts)?
What mods do you have, surely that adds up? What are your driving habits? Do you have stock tires and wheels, or did you go big?
My stock truck as seen in my signature got 18 on the highway at 70 mph. It got 14 around town.
I now have an intake, exhauast, and tuner mods.
I get 21 on the highway at 70 MPH and 12 around town. But pulling my trailer I get about 12 MPG. Because I have the mods.
But before when I pulled my trailer, I got 7MPG and had poor power.
That is the reason it is a modular V-8. You can make it the way YOU want.
Last edited by smokestone52; Feb 2, 2008 at 09:01 PM.
I have the Diablo Sport Predator on 91 tune, modified stock intake and dynamax race bullit muffler w/ side exit 3" exhaust. Mods haven't really changed fuel economy, but mileage improved after the truck passed around 10,000 miles. Truck has 28,000 miles on it now.
Thats not the "TRUE" milage. Your PCM uses a mathematical formula (how much gas is used, injection timing, air temp. engine temp, speed, etc...) to give you a rough estimate of what your getting for milage. I don't remember the exact way it calculates the milage, but it's more of an educational guess then an exact science.
That would be why I included the bit about hand calculating it. Not that it matters, I check every fill up and every, and I do mean every time, it’s within a tenth of what the computer says.
I drive 60-65mph on the interstate...that is how I get great mileage. I have had the onboard computer display up to 25mpg before after about a 10 minute drive, however, as soon as I hit that first red light, the mpg nose-dived. The highest mpg I personally calculated at the pump was ~21 after a long trip on the interstate. Best mod for good gas mileage: SLOW DOWN!