I've recently (2 tanks so far) began tracking my MPG's... On my most recent tank, I got 12 MPG. The one before that I got 11.5 MPG... This seems really low to me. My truck now has 38,000 miles on it, and is completely stock. The air filter is only a few thousand miles old, and is still very clean. I also keep my oil fresh, and I'm currently running synthetic. I drive very mildly, rarely ever flooring it. I accelerate slowly, trying not to go over 2500 RPM.

But is suspect one of the problems is my driving conditions. My primary driving consists of city and traffic conditions. My commute is about 20 miles each way, but takes about 45 minutes each way. I'm sure this is bad for mileage, but isn't 12 MPG still way too low for a stock truck???

Even on the most recent tank, about 100 miles of it were driven on the highway (70 MPH-ish). Still I only got 12 MPG..??..

As far as maintenance, as I mentioned I change the oil regularly, keep all filters clean, had the tranny serviced, and changed the plugs using Autolite HT1's. I keep the tires rotated and inflated appropiately.

I guess I really never noticed it before. But I previously had a NBS 2004 F150 SCrew with the 4.6, and I averaged 15.5 MPG. I just assumed that I was averaging about the same with the 5.4, since that's what everyone said would happen...

Any ideas???

 

I'm no expert on this, but it seems to be about on par with the 5.4L and 3.73's.

A 20 mile commute taking 45 minutes is a pretty slow average speed, probably alot of stop/go/idle time to suck up gas.

My '05 with the 5.4L and 3.55LS rear end gets about 13.5-14 depending on my mood and (Atlanta ) traffic. The 5.4L was never know for it's economy.

That all being said, I took a road trip to Arkansas last month and saw about 18.1MPG average round trip with very little driving once we got there - had the cruise between 70-85 most the way out. This kind of trip is where the 3.55 may make a difference.

Also, if you're using the trip computer for your mileage, I've heard they can be erroneous for some people, mine seems to be about dead on, but keep that in mind!

 

That is not too bad. I have a 07 4x4 screw with the 3.73 gears and that is about what I am getting. I have been getting anywhere from 12.5 to 13.7 with mixed highway and street driving. If I was doing as much street driving as you I am sure it would be much lower.

 

cause you have a 6K pound truck.....with a underpowered engine lol.

 

Thanks guys, it makes me feel a little better. It seems every week I see posts of people with raised 4x4 5.4 4.56's getting like 18 MPG. But yeah, to Pats point, a heavy truck isn't going to get good gas mileage.

 

ye i mean....im getting a average of 12....on regular...edge level 2...in my lifted truck with 38's.

so...kinda blow.s

 

I don't know what I would get with mainly city driving. I drive a mixture of city (1/3) and highway (2/3) for my daily commute. I get right at 15 mpg all year 'round.

When I do long freeway drives I can count on 18 mpg. My person best is 18.7 mpg.

We just got back from a LONG vacation through the western U.S. pulling our travel trailer. Multiple mountain passes of 4,000 to 7,000 feet every day, a few in excess of 10,000 feet. Air temps in the low 100's every day. These trucks pull like a pack of mules. My truck handled everything I threw at it.

Our TT is a 6,000 pound (loaded) giant brick on wheels. Over a grand total of 3,500 miles I averaged 10.5 with a range of 9.2 to 11.7. The 9.2 was fighting headwinds for 2 days on 84 through southern ID and OR.

These are REAL mpg's, not some meter readout. Happy camper here.

 

What are you running for tire pressure, and are you sure the gauge you use to check them is accurate?

I don't know what size tires you're running, but if they are stock 18", I've been running 43lbs. in the front, and 45lbs. in the back when not towing or carrying a load. This has netted me minimal tread wear, very even tread wear, and I am averaging 15.4 mpg. I get about 13.5 around the city, and about 17 on the highway. I have a 5.4 with 3.73 gears and I don't drive to conserve, but I also don't "fly" everywhere.

You've covered all the other bases I can think of, so maybe it's just time for a compression check, or injector check.

 

Mileage is about right..... I get around 11.3 to 11.6 city driving. I always start on a new tank with the thought of getting good mileage, 'this time'. I cruise, accelerate slowly, creeping up to freeway speeds..... for about a day. Then, I just forget and drive the beast. It's heavy, rides nice, accelerates ok with tuning. Long trips ( OC to Mammoth) I can average 16+ which isn't bad since the speeds vary from about 70 to 85, and it's pretty much all uphill ( sea level to 7K'). On the way back, I'll get over 19. Towed my skiis to Laughlin @ 75+ and got 17, so I can't complain, I guess. My mileage is never that great, but man do I love this truck.

5.4L,4x4, Screw,factory 20's, tonneau cover, 3.73's, and I figure full of gas w/the heavy a@@ fiberglass cover, I'm over 6Klbs. easy.

 

The 5.4L is definitely not underpowered. If you ever get a chance to watch the sales video's from Ford, they explain that the F-150 is tuned (programmed) for the smooth take off that so many whine about as being slow. The whole powertrain is programmed for a comfortable ride without neck jerking acceleration you find on other brands of trucks. While many find this annoying, the Ford does deliver a far better ride while towing. Of course, you might want to turn off the O/D while towing like the manual tells you to.

The 5.4L in the Expedition is a completely different monster all together. My wife's Expy really gets up and scoots. Same engine, just not programmed the same.

 

I think the towing tuning pitch is just that. A pitch. An excuse for sloppy programming and likely a response to SOOOOOOO many questions / complaints. Tuning made a world of difference on my truck. Even after the most recent dealer PCM flash (1-2007), there was too much delay on the drive by wire. Prior to tuning, it was a disappointment. I was certian my old '97 xtra cab with the 4.6 was more robust. I've had US trucks for over 20 years, so I have some frame of reference. I have found my truck to be way more fun to drive after installing tunes. I wasn't looking for a race car, just something that was more functional. Using the towing tune, I have no complaints either. Now mileage, that's another story...but I don't have far to go so I really don't care. I do agree about the smooth ride. I've had a number of people ride with me and comment about how much they like this truck. In fact, a recent comment was " I didn't know they made trucks this nice". Underpowered? I don't think so. Not optimally programmed? Probably, even if it's claimed for towing. After working some other small bugs out, that would be my only complaint on this truck, and even that issue had a relatively easy solution.

 

They're lying....

 

Traveling 20 miles in 45 minutes equates to an average speed of 27MPH. You say you're getting about 12MPG under those conditions and still 12MPG during highway speeds?

12 MPG doesn't sound too far off par, but I think you should see a little more difference in those two driving situations.

 

sounds about right, im up to about 13.5-14 mpg with my truck in the city. But used to see 12-12.5 all day long before i started modding

 

Youe mileage reflects mine very closely. My travel trailer is about 1,000 lbs lighter than yours and I get about 1/2 MPG more when pulling it. As you said, 18 MPG traveling empty is normal but I did break 20 once under ideal conditions, alone and at moderate speeds of 60-65 MPH. on a single trip of 300 miles.