Do you know when the spark plugs were changed last?

 

Yes, I changed them June 2017, at 88,000 miles. The truck now has 92,000 miles.

 

Have you changed your air filter? Could you tell us what you have done to try to help your fuel mileage if anything? Do you have OEM wheels and tires? Factory ride height etc.?

 

Yes, I changed the oil, air filter and plugs all at the same time back in June. Just changed oil again this past Sunday . Everything is factory, except I did add a catch can. Haven't done anything else. I expected much better mileage when I bought this thing since it was advertised as 15-21 mpg. Never thought I would get city mileage over the highway.

 

my mileage went down, then I changed my trans fluid and rear diff fluid and i am back up. the rear diff was pretty dirty and seemed like it go some water in it. I will now change the rear diff every 25k miles. 50k was too long.

 

Do you have any modifications? Tire size, tuner, gear ratio changes suspension? Any mods at all?

 

Don't feel bad...my 2014 averages 14.4 mixed driving. I am stock except rims (stock tires), leveled with Bilsteins, and a catch can. Mine is a 14 XLT 4x4 with MaxTow at 25K miles. I too bought the EcoBoost for better MPG but have not gotten as promised. I have a buddy with identical truck as mine (14 XLT MaxTow with 57K miles) but with 5.0, 4" BDS lift and 35 x 12.5 tires and he is getting 17.2 mixed. IDK

AK4wheeler

 

LMGTFY

 

LMGTFY

Believe me, I've searched and have yet to find an answer.

 

2012 with 180,000 miles.
34" tires and I get 15 at 70mph.

 

One thing I have found out, is that these trucks with the same engine are getting totally different mileage. Your getting roughly the same mileage as me, but your tires are huge and are driving 15 mph faster than me. Go figure!

 

Do you have the 6 speed transmission?

I saw an increase in MPG when I changed my rotors. The old ones were warped and dragging. Went from 14 to about 16-17

 

, changed my rotors 2 months ago (they were terribly warped), things were vibrating off of the dash when I slowed down, and yes I have the 6-speed.

 

I read a post from a while ago that suggested the OP to warm the truck up with a 10 mile drive, get on a highway, set his CC at 65 and drive until he feels the average mpg on the dash display pretty much settles down and see what the mpg reads. I am going to try this just to see what happens. The one thing that Ford has done right on my truck is to make the computed mpg very accurate. When I do the math on paper, I get almost exactly the same numbers, so this test should be pretty accurate. Just need to keep the winter blend gas, wind and temperature in mind.

 

 

I agree with most of whats said here. But i will add that i have noticed a decrease in my mileage with age.

Approaching 60K miles and Ive lost a on average 2mpg overall with no significant changes in driving or mods.

I keep on top of maintenance aswell. Full synthetic every 5k, plugs done every 20k or so, clean air filter, new pads and rotors.

The only thing i can think of would be carbon build up. I'm planning on borescoping the valves to see whats going on. If there's any significant buildup ill pull the intake manifold and manually clean all the valves.

 

27...In a 3/4... On 35s...Okay.

Anyhow, I don't believe I have seen that you cleaned the map sensors. It's always one of the suggested things to cross off the list with plugs and whatnot in restoring lost mpg. May not make a hill of beans, but it's quick and easy. And even replacing the sensors is cheap.

With your heavy wheels and tires and whatnot, and your configuration, your mileage seems about par for the course to me.

Sent from my Moto G (5) Plus using Tapatalk

 

Sorry, I know there are some post regarding this, but most are upset about only getting 16-17 mpg on a bad day. My truck that I bought over a year ago now has 92,000 miles on it and since I got it, has never gotten over 15.5 mpg on a fill up (figured on paper). I'm saying this is the best I've gotten. Spring, Summer, Winter, Fall, no difference. I drive on a 55 mph highway 40 miles a day and I keep it at 57 mph or less.

I'm hoping someone on this forum will have suggestions as to what I can do to increase this.

Has anyone removed the cat or cleaned them out?

 

Unless you are throwing CAT efficiency codes - I would leave them alone.

Either way the CATs are welded in. Cleaning them does not really work nowadays. Sorry.

 

Sorry, I know there are some post regarding this, but most are upset about only getting 16-17 mpg on a bad day. My truck that I bought over a year ago now has 92,000 miles on it and since I got it, has never gotten over 15.5 mpg on a fill up (figured on paper). I'm saying this is the best I've gotten. Spring, Summer, Winter, Fall, no difference. I drive on a 55 mph highway 40 miles a day and I keep it at 57 mph or less.

I'm hoping someone on this forum will have suggestions as to what I can do to increase this.

I have a 2012 w/ 180,000 I get an average of 11mpg and 7 to 6 towing. 6" lift 35 tires. Not a good decision to lift a 3.5 it constantly needs gas to maintain torque. The engine constantly works would be much better of with V-8

 

Welcome to the forum, Cliff.
I hope you understand that all engines need gas/fuel to maintain torque. They all use more fuel when lifted and rolling on oversized tires. The 3.5 Eco makes alot more torque than the only V8 F150 choice, the 5.0.

 

I understand this thread is fairly old now. I just purchased a 2014 f150 XLT with the 3.5 eco boost in it and have been appalled by the fuel economy. I get 12.8 city when I purposely stay out of the boost. And mixed driving is 13.8. The vehicle in bone stock. 145k miles. I just got it an immediately did oil change, spark plugs, and air filter. Along with a new high pressure fuel pump and alternator.
The odd part is the calculated mpg on the dash is different than what I calculate at fill ups. But when I check tire size I am still stock and gps speedo matched with the truck as well.
I am not getting any codes. The timing is behaving normally. My boost does seem a tad low. Suspicious of a boost or exhaust leak. Any suggestions? I have Rebuilt engines before but we only needed to get 2mpg on those so I’m at a loss here.

 

I understand this thread is fairly old now. I just purchased a 2014 f150 XLT with the 3.5 eco boost in it and have been appalled by the fuel economy. I get 12.8 city when I purposely stay out of the boost. And mixed driving is 13.8. The vehicle in bone stock. 145k miles. I just got it an immediately did oil change, spark plugs, and air filter. Along with a new high pressure fuel pump and alternator.
The odd part is the calculated mpg on the dash is different than what I calculate at fill ups. But when I check tire size I am still stock and gps speedo matched with the truck as well.
I am not getting any codes. The timing is behaving normally. My boost does seem a tad low. Suspicious of a boost or exhaust leak. Any suggestions? I have Rebuilt engines before but we only needed to get 2mpg on those so I’m at a loss here.

Seems about right.

 

Have you performed a KAM reset before? Id disconnect the battery for about 10-15 min then take it for a drive.

Any chance you have forscan?

 

The battery was disconnected the whole time I was changing the alternator so that has been handled. I don’t have forscan, but I did get the auto meter dash control unit since I wanted to get live boost readings without hooking up a sensor and finding a place to put the gauge.

DASHCONTROL OBDII DISPLAY CONTROLLER, FORD F150, 2009-2014

DL1201U DashControl, Ford F150 09-14

www.autometer.com

 

The next Gen truck (2015 Aluminum) got lighter.
The next Gen Ecoboost (2017) got dual fueling.
So yes, fuel efficiency improved by as much as 20% or more. Depending on how the truck is used, it might be 30%

 

The next Gen truck (2015 Aluminum) got lighter.
The next Gen Ecoboost (2017) got dual fueling.
So yes, fuel efficiency improved by as much as 20% or more. Depending on how the truck is used, it might be 30%

Oh that does make sense. And I guess I do have the heaviest option of my gen. Super crew cab with 6.5ft bed. 36 gallon tank. I’ll update in case I come up with any smoking guns.

 

You do.
But you arguably have the most planted F150 for towing.
And towing a house is the great fuel mileage equalizer! Lol They all suck, literally.

 

Hey I can get 20+ on the highway but those short stop/go trips suck. Literally.
Should get better after April, at least here. (Gas blend)

 

Sorry, I know there are some post regarding this, but most are upset about only getting 16-17 mpg on a bad day. My truck that I bought over a year ago now has 92,000 miles on it and since I got it, has never gotten over 15.5 mpg on a fill up (figured on paper). I'm saying this is the best I've gotten. Spring, Summer, Winter, Fall, no difference. I drive on a 55 mph highway 40 miles a day and I keep it at 57 mph or less. I'm hoping someone on this forum will have suggestions as to what I can do to increase this.

I was have same problem with my 2015 f150 3.5 basic. No turbo. My fuel economy went down to 14.4. Ford say this truck life span is 250,000miles. I have 255,000. My mechanic said to use Lucas cleaner with every fill up of gas so I went and bought a quart size bottle of Lucas. Read the label to measure how much Lucas per gallon of gas. After going thru one quart Lucas measuring it at every fill up my fuel economy has gone from 14.4 to 17.8 and still counting upwards. Hope this helps. No I don't work for Lucas or ford I am just a f150 driver so this story is true and not advertising hoax.

 

I would be excited with 15 on the highway. Driving modestly stock height tires parts etc. I get 11.8. City is 9.2. South texas.

 

Yikes! That’s not good.

 

You're getting good then try12.5 all time