i did a lot of searching about mpg and read about people getting 20+ mpg in their 09 F150's with the 5.4 engine mix city/hwy driving. i was thinking to myself... "who the **** are these people??? honestly"

and now, this is the first thread where i've seen some REALISTIC *** numbers, FINALLY!!! damn....

09 F150 5.4 with 3.73 screw plat, 20 inch wheels, 3500 miles, no mods. i dont drive my truck like a jackass (that goes both ways). using the computer mpg reading:

11.9 mpg stop and go freeway driving for 17 miles. stop and go 90% of the time

16.0 mpg freeway driving at 70-75 mph driving for 17 miles.

13.8 mpg city driving for 7 miles.

a mixture of all this after a full tank equals roughly 14.1 mpg.

 

How'd you get 3.73? Is it a 2-wheel drive? When I configured my Plat, there was no getting the 3.73 that I can recall, except maybe if you chose 4x2? Is it even possible to get a Plat NOT in 4x4? Just curious...

 

sorry forgot to mention, 4x4

and YES: 09 plat, 4x4, with max trailer package hence the 3.73 axle.

 

Oooooh, yes, that's right. Now I remember, the only way to get it was to also get those massive side-view mirrors. I knew there was something that prevented me from ordering it with the 3.73. Gotcha now, easy to forget after all these months.

 

I've never read anyone claim that in any kind of mixed driving they got 20mpg with the 5.4L. Where did you do this research?

 

big mirrors indeed... handy for towing and "manageable" around town believe it or not. but would have been nice if they had an auto fold option

 

i dont know buddy... i've read such "claims" in various forums and sorry, i'm too lazy (and old) to go back and search for said "claims" to post my "research findings" oh well.

the net is: not sure how you guys are getting such good gas mileage??? i just filled my tank this evening, averaged 13.8, traffic has been heavy lately due to bad wet weather but damn me, talk about the mpg being damn sensitive to conditions.

maybe its the big *** mirrors

 

I've read almost every thread on this forum that discussed fuel economy for the 2009+ F-150's and never read of anyone getting 20mpg with a 5.4L except that thread I referenced in post 5 above. That's why I asked.

If one drives in city conditions (like highway stop and go), do not expect to get near highway fuel economy. Vehicles use a lot more fuel accelerating than at a steady speed, whatever that speed may be.

 

I have an '09 5.4L SC 4x4 with 3.73, stock tires. In Iowa, before October, I've had 4 tanks of fuel over 20.0 calculated mpg using (almost always) Kum & Go 10% ethanol fuel. Truck is about to roll 25k this next week, was new first of May. On all 4 tanks, I was going long hauls to NW Iowa or to Kansas City non interstate, so average speed was under 60mph on flat land driving. I've noticed in my case that average speed is VERY critical to mpg. Increase average speed 5mph, drop mpg by about 3.

Just another point of reference. Iowa has switched to winter fuel, and my 2 week average mileage has dropped overall 1.7mpg so far as a result.

IowaAndy

 

Well, I had heard the same rumours about pushing the 20 mpg mark... so I'm doing a test... I've got a 09 screw 4x4, 8500 miles on odo, with 3.73 rear end, and the 18 light truck tires (i'm guessing more rolling resistance than the passenger tires). I commute approx 40 miles (70 km's round trip) of highways, with 1 to 2 miles of in town driving.

First leg of my test... Speed limit driving only, with cruise. Our limits are 90 and 80 km/hr here in canada, which is like 58 mph to 53 mph or so. So far i'm averaging about 16.8 mpg (veh info). I'm used to driving 110 km/hr which is just shy of 70 mph... I'm checking to see what the difference is in fuel economy between grandpa driving, and my regular driving style.

It's painful going that slow... ya, i'm saving fuel.. but i'm also on the road for a longer period of time. on my next tank, if i only see a savings of a few mpg's, than i'm going to pony up the cash for the benefit of driving it like a normally do and never worry about squeezing out the max mpgs.

I've also got a tonneau cover (not sure if it helps) and the towing mirrors (definately doesn't help). hoping for great results.

Luc

 

 

Went up North Thursday to do some bow hunting and set the cruise at 70 mph and ended up with an avg of 18.4 mpg (the best yet)

Came back last night and it was windy as hell, had it set at 70mph and averaged 15.6 mpg.

09 FX4 20"s 5.4L

 

Well all in all I think we have come to the general conclusion that these trucks are not owned because of their great gas mileage. I will admit for whatever reason that I thought the 6 speed transmission would help. Not the case. The thing that baffles me is why doe my 09 get worse mileage than my 06? Both trucks came from the same dealer and now are driven by the same person in the same area and the trucks are identical except for the year of mfg. Why poorer mileage in the 09?

Perhaps this question has no logical answer!

 

I get around 17 commuting back and forth to work and have been getting about 19.5-20 on the highway in my 09 Lariat SCrew 4x4. I picked up about 1 mpg when I got a K&N drop in.

 

Raoul= I bought a new 99 f150 and it was a fantastic truck. I put it through places where a camel wouldn't go. Never once did I have a problem, Well except the the time I thought a little mud puddle out in no where would be a piece of cake, had to remove all the plugs, spin the engine over to spray out the water and mud that got sucked in. Got it started after a couple jump starts. But that was my fault. But that 99 f150 was a great truck!