Was on a road trip in a flat area of the province ( which is odd for me usually climbing hills 90% of the time ) got home plugged in my numbers and I got 19.1 MPG! I am so very impressed with my 4.6L and contrary to popular beleif I can get out of my own way regarding power.

 

I got 17.5 in my 2004 F-150 with a 5.4L

 

My wife just got back from a 500 mile trip and got 20.5 MPG in my F150 FX4 4x4 with a 5.4..... I couldn't believe it. She said she never really went over 70 mph and didn't pass anyone. The best I have gotten is 18.7 mpg. The only mods are a 1.5 Auto Spring Kit and a drop in K&N. I hope to get over 20 mpg after an exhaust, Airforce kit and 1714.

 

Believe it or not, the best i got with my F150 5.4 was 21mpg,
on the average 19.5

 

wow, the best we get with the 4.6L is about 16.5 mpg all stock except K&N. normally getting about 13.4 mpg.

 

It is very impressive that a vehicles with that kind of weight can get that high of gas mileage. This truck, with respect to weight, gets the best gas mileage out of any fullsize I have owned to date.

 

I've been getting about 16 MPG, but travelling at 85 MPH most of the time. I know it's fast, but decent milage. My cousin also has new 04, he did have problems with his milage and the dealer installed a higher temp thermostat and now he gets 20 MPG at 65 MPH. His complaint was only getting 12-13 MPG at the same speeds. Quit the increase for only a thermostat. He measured these ratings over long trips, so I think they are reliable. I think if I dropped the speed on mine, I could probably get the same results. Bu its a truck, and a ford at that. All my previous fords never got more than 15 MPG, no matter what mods, so I really have no complaints about hte milage.

2004 FX4 scab w/ 18"tires.

 

I went to Modesto from Fresno using the freeway I Got 19.2 one the way up and 20.1 on the way back. I was pleased. My 02 would only get 17.

 

At 19mpg are you using Canadian or US gallons? A Canadian gallon is 160 onces or 4.54 litres and a US gallon is 128 onces or 3.785 litres. It makes quite a difference. If it is in Can gallons it would only be 16 mpg US.
Doug

 

I average about 16 around town. I don't think I've ever gotten up to 19.

 

I am using U.S. Gallons as it seems the majority of members are are americans, plus the excel sheet I use is from the U.S. so it was set for U.S. Gallons.

 

this is all fine and good.... but the driving style that delivers me 13mpg is way more fun!

 

Good stuff. Figured I check just incase. 19.1 US is very good. I usually run around 14~15 mpg (us) with my 5.4 cruising around 70~75 mph.
Doug

 

we get about 15 mostly highway driving. is there any reason we would get that low with the 4.6?

 

Maybe it's a difference in fuel, location and altitude. I'm near the Pacific coast and normally see around 12 mpg with no highway miles. On the couple of occasions where I've made a run down to Seattle the trip mileage has been almost 19 and the average for the tank has been about 15. That would equate to roughly 50% highway and 50% short trips in town.

On this tank I was at 11.5 (by the Lariat computer) before my trip. I'd burned about 1/4 - 1/3 of a tank before I ran down to Seatac. The current average is 15.5 with about 1/4 tank left. That's with a Lariat 5.4L 4x4. A two wheel drive version ought to do better.