Im getting 11 MPG average from a fill up.. (not going by overhead display)
80% of my driving is highway....

I know i can get better MPG than im getting now....
My truck is a 2004 2wd 4.7 with a manual tranny and 121k miles...

1st bought truck i got pretty good MPG.. Then i decided to add 3 inch suspension lift as will as a set of 35 x 12. 5 x 20 tires.... (which i knew would really hurt MPG)

Only mod i have under the hood is a dual cone K & N intake tube (which i know could use a good recharging).. I do have a 2 chamber flowmaster muffler.... Im also still running stock plugs... Truck runs great just power could be a lot better (even for the 4.7) and would love better MPG...

would love any suggestions you might have

 

more gears would help and especially since you went up in tire size, efan, proper tire pressure, synthetic oils, lowering the truck, changing plugs.

 

its a truck with a lift and bigger tires........ i don't know why people care about mileage

anyways most of your decline is because the truck is pushing more air. i dont think you are gonna get more than 12 mpg even with mods

 

i myself have never cared bout MPG... Heck my work truck gets 7 MPG... Trying to convince the wifey that i can still get the MPG im getting now even if i add a 3 inch body lift... lol.. So im actually just trying to mantain the MPG im getting now even after adding body lift...

 

Tire size! Did you have your computer recalibrated for the larger tires? If not, then your odometer is reading lower miles than you are actually travelling.

Check the tire specs - notably revolutions per mile. A 35 inch tire makes about 600 revolutions per mile, while a 32 inch tire rotates approximately 650 revolutions per mile. If you changed from a 32 inch to a 35 inch and did not have the computer recalibrated for the larger tire size, it will show that you travelled one mile each time the rear tires rotate approximately 650 times. But, in reality, you have travelled a mile at 600 revolutions, meaning that in this case, your odometer would show that you travelled a mile after you've actually travelled 1.083 miles (1 & 1/12 miles).

Doesn't seem like much, but if you filled up at 200 miles and put 18.2 gallons in the tank, you'd calculate your mileage at about 11 mpg. But in reality, you would have travelled about 216 miles. That would get you close to 11.9. Almost 1 mpg just due to speedometer/odometer error.

You can check your odometer by comparing it with a known source like a GPS or the mileage marker posts along a freeway. Be sure to measure it against 10 miles or more to eliminate any variance that might occur between one mileage post and another.

 

your right tom.. i know my speedo is off and didnt take that into account while figuring my MPG... I need to get it to dealer to recalibrated speedo.. When im reading 60 mph im actually going 69 mph...

 

That's a pretty big difference. Mine is almost spot-on, compared to my GPS. Odometer and speedometer.

My Escape was right on the money with the odometer, but the speedometer on that car read high. It read about 64 when I was going 60 (opposite of yours, I guess). I guess Ford didn't want me to get a ticket.