Yeah I kind of figured lol I know since 2014 that Ecoboost has gotten a tad bit better at mpg but it is what it is lol

 

I have been on this site for years. People are still interested in mpg. My daughter has the same truck as I except her truck has 18 inch wheels, mine has 20 inch wheels. Over the life of both trucks I have gotten 20.3 mpg. She has gotten 23.6mpg. The trucks are both 2.7,3.55rear, 5.5 beds, xlt. Our driving habits are the same. I am trading and getting 18 inch tires. I am convinced the tire size is the difference. I just don't know why ford won't let me buy a 2.7 with a 3.31 rear. That would really be the best mpg. I know what you smart people think, but the 2.7 would do just fine. I don't need the 5.0 engine to pull with the 3.31 rears.I say let the purchaser decide what they want.

 

He fed you a line!!

The engine is designed to run on 87 octane. You only need 93 octane when towing or want better performance, though I haven't noticed any difference stock when running 93. TUNED is a different story, yeah you know it when on 93 when tuned, but stock? Only if you tow with a lot of grades and need the extra oomph.

Switch to regular grade and enjoy. You might want to change up your driving habits a bit, you should be getting more than 21 with the 2.7, unless your doing 80 MPH all the time.

 

i appreciate your help, i should have asked that question here last year when i joined.
i have about 175 MTE so when i'm about empty i'll fill up my 35 gallon tank with the cheap stuff and save a few $.

during the non-winter months i'll hand calculate 23-24mpg religiously. for some reason it drops down to 21.5-22 between November-April.
i drive like my 65 year old father, my 50 mile round trip commute is 75% highway doing 50mph in 9th gear and 25% city where i'm doing 30. all flat country.

 

You're correct, larger tires do take more power and hence worse fuel mileage. But not necessarily due to the rim size which 18" is. It's the circumference that counts. Or, revolutions per mile. It's very possible an 18' wheel could actually have a larger circumference than a 20". It depends on the sidewall height. 60. 70, 75, etc. Which is the percentage of sidewall to the circumference.

 

The drop in mileage during the winter is due to Government mandated fuel blends. Not your truck.

 

It's been quite a while since I chimed in here but I'm still driving my 16 3.5 NA. And the mileage has held up consistently around 21 MPG. I drive a mix of highway and rural, not a lot of city, I would guess less than 20%. I also keep up with traffic which on the interstates is always around 78 MPH. So I'm not a slowpoke by any stretch. My so-called lie o meter is dead on virtually all of the time. It can be and I did adjust it to correct it. After changing from 17 to 18-inch tires, I also adjusted the speedo to correct it. It also is dead on consistently within one MPH at all speeds when compared to GPS and mile markers. I did match the revolutions per mile and matched used a tire size that matched. (Using Forscan) I now have over 180,000 on this truck and all is well.

People whine about mileage all of the time. Usually expecting the mileage to match the sticker. Ford and all manufacturers calculate these numbers using a government-mandated method. They all follow the same procedures. If you're not getting that number, there are literally thousands of reasons why. Mostly you and your particular circumstances. Your driving habits, where you buy your fuel, and what time of the year it happens to be. Octane ratings have little to do with mileage and for the most part, the higher grades are a waste of money. Any benefits would come more from additives.

Scroll through your dash info and note the engine hours vs. idle hours. Calculate the percentage of idling compared to driving and that will be a good start in understanding why your not getting the mileage you expected. I'm fairly sure no manufacturer is required to calculate the amount of idle time. How could they? Obviously, when you're sitting still, it deducts from your actual mileage. Just one thing that folks seldom think of. There are many others.

 

One other note about tires. Tread pattern can make or break MPG. Rolling resistance plays a big factor. The weight difference between 18 and 20 is only a few pounds, but the type of tire itself can play a bigger role. A heavy lugged tire which is great for traction in mud and snow and off road will have horrible rolling resistance where a highway all season will have low rolling resistance.

When we had an, ACCCHHHH, Prius, it came with really low rolling resistance tires, but had zero traction in anything but dry pavement. Worst driving, handling car I ever had, especially when it took 20 minutes to go up a slight hill with light snow on it. The car got 70 MPG highway though with those tires.

 

Sometimes the fuel economy of the 2.7 amazes me. Lifetime is 20.4 calculated (not indicated). That includes 13k miles pulling a utility trailer to the Arctic Ocean and back, according to the towing software I have averaged 18 mpg towing that trailer.

On a recent trip 2200 mile from the Southeast to the Great Lakes and back (no trailer). I got a calculated 25.9 mpg on one leg of the trip, and an indicated 26.9 for the entire distance.

On the Dempster in Northwest Territoriy

 

How does one calibrate the ole LOM? Would like to really dig deeper into my MPg’s

Thanks,

Travis