For all those saying they get better mileage on higher octane gas, have you done the math to see if it is costing more or less per mile? I appears to me that the different between 87 and 91 is a higher percent than the difference in mileage, therefore the cost per mile is higher on the higher octane gas!

 

How are you measuring the ethanol percentage at the pump??? And the 3.73 gear aint helping either.

 

Just the marked ethanol on the pump which can vary, the 87 and 91 octanes were marked 100% gas no ethanol on the pump. I ordered my truck from the factory with performance in mind not fuel efficiency. The result I get have been consistent in the 6 years since delivery. I tossed the idea of factory warranty right after delivery and tuned it, been adding mods slowly since as my budget allows. The financing was solely for a cost reduction and paid off in less than a year. MPG figure are from last May and calculated by hand to check the display, also broken down into cost per mile driven. Price variation since last year and the cost difference between octane ratings have improved the 87 cost ratio to where it ties or is slightly ahead of 91 and 93. Just last week on a 300 mile trip local 93 octane and 10% as marked at the pump resulted in 23.5 MPG.
I'm making no claims for F150 mileage in general just what I get from my truck which is modded and driven fairly hard.
475 cents the cost of a gallon of 93, divided by 23.5 miles driven equals 20.21 cents per mile.
425 cent cost of 87 divided by 18 miles driven equaled 23.61 cents per mile, in prices last May.

 

I find 5.5 mpg difference between octanes a little hard to believe! Then again was the tune removed when running the 87 octane? Do we have apples and oranges?

 

Key success factors are a bed cover - I figure I am 1 mpg up on that and 39 psi in each tire. at least. My 2.7 is 24 mpg pretty consistently, but I am on the hwy with it most of the time.

 

Rapid Red is noted for getting better mileage!

 

"I find 5.5 mpg difference between octanes a little hard to believe! Then again was the tune removed when running the 87 octane? Do we have apples and oranges?"
1 road trip all on the BCB Highlander variable octane tune 80 MPH Sioux City to Ft. Collins. On 87 the truck needed 2+ PSI boost and more. Long drives in AZ, UT, WY MN, on 91 or better it pulled vacuum rarely going into boost. Wife and I retired 10 years ago and do long cross country road trip either in her 2016 Edge Sport or my 2017 XL.KM

 

The tonneau isnt netting anything. If that were the case then raising or lowering the ride height on the highway would show dramatic differences.
The biggest factor is tire width & weight I could guarantee mid to high 30s mph with some 205mm wide tires but the traction & braking would suffer.

 

 

Attached are photos from a recent 2200 mile trip from the Southeast to the Great Lakes area and back. I was driving 65 most of the way. The camper shell had no negative effect on my fuel economy.