the gov site reports 15/19 for both on a 2wd.

 

I have the 4.6 SCREW, and i have yet to get 15 city. I average 13.9 city, without gunning.

 

Use this:

 

I have the 4.6 Scab. I've been getting right at 15 mph with local driving only. Not quite 1100 miles yet either. Very light on the pedal I might add.

 

i get 15mpg 50/50 with alot of WOT.

 

I'm getting 18.4 in mostly rural driving with my 4.6L, stock vehicle with bed cover.

 

I have the 4.6L in my supercrew, and I just filled up today after doing half a tank of just city driving a lone, and I came out at 11MPG in the city!!

On the highway, I average 17Mpg. (most of the time I have a light foot also just due to the high gas prices)

 

my 4.6 reg. cab (bone stock) with bed cover is averaging 16 mpg
60 / 40 city - hwy ...

 

sure they're gonna be close. This heavier truck makes the 4.6 work a little harder. More downshifting equals higher avg RPM equals more fuel consumption.

with the 97-03, the 4.2 and 4.6 were close in real world mileage for the same reason.

 

Here in Cincinnati there are a lot of hills and I have been getting 17 - 18 mpg in a mix of 60/40 highway/city driving and that's with the winter blend gas. I have a reg cab 4x4 with 3.55 gears and a bed cover with Magnaflow exhaust. I usually cruise about 75 mph on the expressway and I don't have a light foot. From what i have read on here, it seems most 5.4 average out about 15.5-16 in the same type of driving.

 

Im not sure if any of you with bad gas mileage have tried this. I was seeing 13.8 mpg on my info center forever. The other night I just pushed reset and I was seeing 16.8 mpg and even better in some situations. and this was all city driving without babying the truck. Before I was calling BS on all the people saying that they had the 5.4 and were getting 18 mpg on the highway and such. Its very possible!

 

My previous truck was an '04 F150, 4.6, 3.55 gears, 2wd, S'Crew. I averaged about 14.5 mpg, with about 50/50 city and hwy driving, but alot of the hwy driving was during traffic times. Now I have an '05 F150 with the 5.4, 3.73 LS, 2wd. Believe it or not, my average has actually gone up a little; now I'm getting about 15.25 mpg.

As mentioned earlier, I think it has to do with the 4.6 having to work hard and rev higher to maintain the same speed. Also the 3.73 gears really help out on the low end (cith driving, heavy traffic conditions). Better gearing allows the engine to not have to work quite as hard.

 

I get about 15.5 mpg in my SCREW w/ 4,6 and I run 20 inch wheels with 285/50/20's. I lost about 1.5 to 2 mpg's with the 20's on it. I have a pretty heavy foot too, so I could probably do better if I was all that concerned about milage. I probably wouldn't be too happy though if I was in the 11 mpg range.

 

On the other hand....

I have an 04 FX4 with the 5.4 3V and 3.73LS and average 15 city and 18 on the highway. After upgrading my exhaust and intake I'm now getting 16 city and 19.8 on my way to Texas. I am easy on the throttle and try to stay below 2000 rpm.

 

I'm not sure what the specs are on the 4.6, but I'd venture to say that the 5.4 is just a lot more efficient engine. 3 valves/cylinder, variable valve timing, direct ignition, etc...