My second fillup was with premium gasoline, and the vehicle showed 16.5 mpg. There were couple of changes since my first fill up besides the premium fuel. About 65% after the fill-up I changed jobs. Before, my commute was mainly in town with stop and go traffic. Now my commute is mainly highway with slow but steady traffic. Speed is anywhere between 20 to 60 mph. Additionally, I added line-x and tonneau cover during the second tank. So the 16.5 mpg was 65% in town and 35% hey.

I also had the third fill-up with premium gasoline and it is currently sitting at 110 miles at 21 mpg. It went all the way to 22 mpg yesterday, but we had a few in town runs today which reduced the mpg a little bit.

I am just amazed at this 3.5 ecoboost engine. I never expected such mpg numbers. Even 16 mpg would have been great considering the fact that my Ram 1500 with 3.21 gears only gave me 14.5 mpg on the same route.

I am just so happy right now. Enjoying the truck everyday. I am trying to find reasons to drive it.

 

 

Replace stock wheels/tires and pay the price. Yeah, your getting what it's going to get. Also don't try comparing a Diesel to a gas truck when it comes to MPG, unless the diesel was old, worn out, or highly modded with huge injectors, it will always do better than gas. Sice you went and replaced the stock tires, you have no baseline for MPG to compare to, but there is a 95% chance it is the tires.

 

Did my third fill-up over the weekend. The vehicle showed 19.6 mpg and hand calculated was 18 mpg. It was about 85% hwy and 15% city. The hwy miles were mostly slowing down and speeding up traffic anywhere between 20 mph to 60 mph with some occasional halts. I did use premium gasoline (91 octane). I am pretty happy about the results. I am very sure if I drive straight hwy at about 70 mpg, this truck could give 22 mpg plus. Mine is a 2018 3.5 Ecoboost, XLT, 302A, Supercrew. The truck is stock with the only modifications - Bak Revolver X2 tonneau cover, Line-X bedliner, and wheel well guards.

 

2005 F150 Lariat 5.4 190k So 2 years ago I rebuilt my Transmission 3 times at a shop that were the old owner sold me a POS rebuilt tranny. The new onwer the replacement my trans with a new but my gas mileage was bad around 12.3 to 13 2 mph just thought it was the norm. Two months ago my torque converter when bad and I replaced at the same shop because the new owner figured that the TC was the problem the whole time and we worked out a deal.

After the TC replacing my gas mileage went up to 16 mpg on the highway with a 5.4 liter and runs like a new trauck. So guys you may what to check those old torque converters out there and repalcement them before they blow up.

 

 

2016 Platty 4x4 with the 3.5 Eco. Leveling kit and 35's (Discovery STT) and I get 13 MPG. That sucks. Ill go with a less aggressive tire next time.

 

Nearly emptied my tank today, forgot to fill up last night. Had less than 3 gallons when I filled, and 33 miles to empty. Getting 21.7 and 755 miles to the tank. Not bad for a big heavy brick on wheels. Pound for pound as good as a Prius.

 

Do you really think I'd read damn near 1200 posts on this ? NO !

I don't know if any of this has been posted or not, or if you all haven't figured it out yet ?

If you want to save fuel = FLOOR IT !
To get to the speed you want or the posted speeds on the highway.

Yes that is right !
I read it directly from a " Popular Mechanics " magazine many years ago.
Aside from the basic crap we all know about, they stated you'll use/burn more fuel ***** footing/slowly getting up to speed that is posted vs just gunning to get to that very same speed !

Another thing is (if not already posted ? )
Check out " MythBusters " for fuel mileage on trucks or something like that ?
You'll get a good laugh at how many people are so wrong when it comes to tailgates on pickup trucks, to a point you'd like to question them on their intelligence ?

It's funny how so many people think you'll get better gas mileage with a tailgate removed vs having it up in place, while this is false !

Fuel up in the early morning = fuel is cool/ more condensed = better ratio per price per gallon for what you get.

Everything here may not seem like much, which you are very correct !
Yet over time everything adds up & equals more !

 

So I have a 2018 F-150 Lariat w/6" lift kit running Nitto Grappler II AT 35" x 12.5 tires all around. No other mods. My gas mileage in the city varies between usually 14-15, expected. Here is my problem, just got back from San Antonio from AZ about a 1600 mile trip and my MPG average was just below 12 mpg!! In the words of Vince Lombardi, "WHAT THE HELL IS GOING ON!" OH YEAH HAVE A 5.0 COYOTE ENGINE