No, this isnt your typical gas mileage thread. I understand that these trucks are just that, trucks..and dont get the mileage of a Honda Civic. My question is, how many miles should be on the truck before I start trying to calculate my gas mileage? I know that the more the motor breaks in and clearances on the piston rings get closer, it is supposed to get better mileage. The reason I ask is because I filled up tonight with 23.5 gallons, when the fuel gauge was on empty, and I had driven 293 miles. If you do the math, this equates out to roughly 12.5 MPG. I have been very light footed in the truck, and havent raced it around at all. Should I be able to expect an increase in mileage as I put more miles on it? The truck only has 600 miles now, what are your opinions?

 

I just got to 1000 miles and I cant beat that mileage per tank..I average 11.2 MPG

 

I got a 04 4x2 Screw / 3.55 rear / stock tires with 17, 700 miles on it. I get a solid 16mpg local driving. In two weeks I’m tripping to Lackland AFB, approximately 2,400 miles of highway driving, and I’m hoping to see 20mpg plus.

I think when you get a few more miles on your truck you will see your mileage increase to where it should be

 

I'm at 20,700-something in a 2WD Supercab Lariat with 3.55s. My daily commute is about 40 miles round trip, mostly highway, I average about 17 mpg at 65 mph. In town, that dips down to around 15 mpg. When we're going to Texas, unloaded, at 80ish mph, I'm getting 14-15 mpg. Coming back, loaded, with a 5x7' U-Haul, I'll see about 10-11 mpg.

 

The owner's manual says to wait until the truck has at least 2000 miles before calculating mpg. Then average mileage over 5 tank refills.
My own experience was that gas mileage stabilized at 850-1000 total miles.

 

In my '05 SCREW 4.6L with mostly city and little highway, I've consistently been averaging 13.9mpg, with the one tank that was half highway I got 15mpg.

I have figured out that it takes 25.5 gallons to go from low fuel light to first click. My low fuel light came on just as I was pulling up to the pump.

 

Check your OD ... mine was off by 6-8% on the low miles side of the speedo ... that makes the mpg look a little worse than it really is. A couple other people I know had a similar observation.

 

On the gas mileage on these trucks some information find useful;

1. The trucks need at least a 1000 miles on them before you can get a decent mileage record.

2. Don't top them up beyond three quick clicks. The large flat tank can be topped up a long way, this is not something you want to do. See owners manual.

3. If your driving is short hops, engine cold, expect terrible mileage. 12 range or even lower.
They don't get good mileage cold. This can be verified with a Scangauge or other mileage tracking device.

4. They are heavy and they don't like 'stop sign to stop sign' driving.
No one gets good mileage on these trucks if you have to keep pushing 5-6k up from zero.

5. Don't check your mileage every day. Let the tank get down some as it is totally inaccurate if you try to measure with small amounts. Gas expands and contracts a LOT based on temperature.

6. The trucks 'freewheel'. Simply put, they coast like an old time overdrive transmission. Take your foot off the gas much earlier, and you will see a much bigger increase in gas mileage than on most trucks. Also you can cut your brake dust in half or more, by learning when to start 'coasting' down to a stop. It's different with these drive by wire trucks than other trucks. Coming down a long gauge these things coast like they were in neutral.

7. The drive by wire system has a difference from cables in that pressure on the gas pedal is not at a 1 to 1 ratio with power.
Long winded way of saying that if you are cruising on a slight upgrade at 65 mph, and getting 17 MPG, and you push the pedal down a little more, you will still be driving at 65 mph, but now you are getting 15 MPG. The small bit of extra throttle just makes the mix a little richer, no power gain. It seem to be because the throttle is more sensitive than the air intake control. So some guys get much better mileage just because of the way they touch the pedal. This is either bad or good depending on you.

8. Most 're-flashes' seem to help mileage as they slowly work the real life bugs out of the system.

9. This is theory backed by several people's observation and some answers from Ford technicians. There is an original 'tune' on the PCM that is very good for break in, and most shops like to change that tune when you come in for any reason.
Can't prove this, but seems not unlikely.

10. They like lower resistance air filters. K&N, AEM etc. most if not all report better mileage from oil/cloth filters.

11. If you highway (just sustained speeds, not always accelerating) opening up the exhaust a little will help. Just a more free flowing muffler does about as well as a full catback system. For mileage that is.


12. Almost everyone with a Tonneau has reported an increase in mileage on the highway.

13. These trucks don't like hills, or even uneven terrain. I get 14.7-15.3 leaving my place, and 17.5-18.5 returning on the same road. This is on a long grade you can't see with the naked eye, but you can feel it on a bicycle. Or in the F-150...

Check your Speedometer with your GPS or on the mile markers. Mine is dead on, but only after changing the IP and the tire size. 5% off is about normal on some of these trucks.



Around town if you can get EPA of 15, consider yourself lucky. On the highway you should be able to blow EPA out of the water.

I'm getting 15 around town, driving normally, and 22-24 on the freeway staying with LA traffic.
(Speed limit? I do'n need no stinkin speed limit.)

STX 4.6 Reg cab.
AEM intake (before that K&N filter in stock box)
Magnaflow exhaust.
Superchips.
Fold-a-Cover tonneau
And about two hundred pounds of other mods.

 

2004 FX4 Screw
Highway - 15 mpg
City - 12 mpg
Mix - 13 mpg

1999 BMW 328I
Highway - 30 mpg
City - 18 mpg
Mix - 22 mpg

It's kinda funny how my truck's mpg varies so little between highway and city, while my car varies GREATLY between city and highway.

BTW - $2.64 for regular unleaded here in San Diego, and $2.95 for premium!!! Guess which car I'm driving more!!!!!

 

that's great information ChrisAdams....a lot of god points in there.

Another way to maximize your milage is to keep the truck as light as possible....every 200lbs lowers the average gas milage by 1mpg.

 

Hey! I just Graduated!!!!! YEE HAW!!! this is post 102!!!

 

gpaje, a question please.
What do you mean by highway?

This is not as lame a question as it sounds. I have asked this of a dozen people in different locations and got more than a dozen different answers.

It seems to vary from 'using the freeway to jump around town' is highway, to 'hitting the two lane, filling at the onramp, and driving at a steady pace till filling at the off ramp'.
Those two definitions account for a very large spread on the gas mileage.

If I do the freeway hopping method I get worse mileage than going surface street. Why? because I have to nail it up to 80 to merge, and then hold that speed for one or two minutes, then blast down and off-ramp into lights. Quick but not easy on the throttle.
I get about 14.7 doing that a lot.

If I do the other method, Filling a block from the freeway onramp, then filling when I get to San Diego (actually out at the Animal Park) I actually average just under 25 mpg. This is along the 15 at about 65 mph. Both are 'highway' miles.

I got 23.2 last time I ran up to Vegas, just on the highway portion. Filling one block from the freeway, filling at Jean, a few hundred yards from the freeway.
This is up the Baker grade, and staying with the legal limits.
You live at sea level, and unless you are going out the 8 grade, I presume you mostly drive on flatland?
Your truck is also quite heavy, I would guess at the top of the mark. Do you have the 5.4? mods?
Chris

 

Wouldn't you be gaining mpg? not loosing or lowering it.

However I still don't see it happening.

 

Yo Chris,

I'm talking about pure freeway driving. I love to go snowboarding, and head to Mountain High (short trip) or Bear (weekend) often.

When heading North on the I15, which has lots of wind resistance and uphills, I get 16 mpg (F150) and 25 mpg (BMW). But heading back home South on the I15, which is against the wind and going downhill, I get 17 mpg (F150) and 31 mpg (BMW).

My completely stock FX4 Screw is seriously a heavy pig, and a 5-speed auto would probably help performance and fuel economy of the 5.4L. But I do have a heavy foot and try to average 80 mph when freeway cruising.

In fact, gas prices and weak fuel economy of my truck have relegated my F150 to mostly an open house sign posting duty and camping. I even added a roof rack to my car to take over mountain bike and snowboard duty, at least until gas prices start dropping.

 

Wow, thanks for all the replies... my question has been answered. I figured that after the motor broke in a bit mileage would increase. Not like it matters anyway, it's a flippin' truck! It's all about driving the right vehicle. Hey it could be worse. My old '02 S'crew Lariat 4x4 was getting about 8MPG in town and 10MPG on the highway, but I never kept my foot out of it as I do with this truck. Thanks again for all the awesome replies..

-Chris