The Ultimate MPG thread.
Senior Member
Joined: Feb 2016
Posts: 206
Likes: 20
From: Denham Springs, LA
Because of this forum and the discussions of mileage, I filled up with Premium before going on a ~220 mile round trip yesterday. My LOM has been adjusted within 5 percent of hand calcs.
My average mpgs jumped from 20.3 to 23.2 (previous average after same trip). The premium was 29 cents per gallon (93 vs 87) more at 3.619/gal. That's roughly 12.5 percent more per gallon. The mileage increase is about 14.2 percent, so I'm money ahead, but barely. Perhaps it will improve more when I've put premium in again (there was about ¼ tank of regular left when I filled up). So I think I will be using premium all the time now. YMMV (literally). I'll fill up again today and confirm the LOM readings with hand calcs (Fuelly) - but I think that in my case, the argument that 93 is better rings true.
My average mpgs jumped from 20.3 to 23.2 (previous average after same trip). The premium was 29 cents per gallon (93 vs 87) more at 3.619/gal. That's roughly 12.5 percent more per gallon. The mileage increase is about 14.2 percent, so I'm money ahead, but barely. Perhaps it will improve more when I've put premium in again (there was about ¼ tank of regular left when I filled up). So I think I will be using premium all the time now. YMMV (literally). I'll fill up again today and confirm the LOM readings with hand calcs (Fuelly) - but I think that in my case, the argument that 93 is better rings true.
Rarely do many drivers have fuel economy on their priority list. I've seen more F-150 owner spending more time and money on larger tires and lift kits that surely isn't going to get them better MPG. That's not even considering those with aggressive driving habits.
5 Year Member
Joined: Aug 2018
Posts: 99
Likes: 24
My new 2018 F150 3.5 ecoboost, super crew shows 15.2 mpg after 350 miles. Everything is stock. Hoping that mpg will improve a little bit from the next tank onwards. I am going to try 91 octane from Costco on my next tank.
Senior Member
Joined: Jun 2016
Posts: 137
Likes: 18
From: Greenville SC
That's a hard question to answer simply.
All I've seen show that higher octane gasoline formulations have SLIGHTLY lower energy *BTU/gallon). But there is more to the story.
In a vehicle without variable timing and cams, no. But if it allows operation without knocking, it might by the tiniest amount. In a vehicle that can make adjustments to timing and cams, probably a measurable amount up to the limits of those controlled variables.
IN GENERAL, improvement in MPG would not be close to the additional cost.
Look at ethanol enhancement ... higher octane, significantly lower energy, measurably lower fuel economy, cost effective if (I don't know any real number, maybe 20%) less expensive than unenhanced. "Pure gas", no ethanol, probably gives 1-5% better economy.
If I haven't confused you enough, let me know and I'll try again.
All I've seen show that higher octane gasoline formulations have SLIGHTLY lower energy *BTU/gallon). But there is more to the story.
In a vehicle without variable timing and cams, no. But if it allows operation without knocking, it might by the tiniest amount. In a vehicle that can make adjustments to timing and cams, probably a measurable amount up to the limits of those controlled variables.
IN GENERAL, improvement in MPG would not be close to the additional cost.
Look at ethanol enhancement ... higher octane, significantly lower energy, measurably lower fuel economy, cost effective if (I don't know any real number, maybe 20%) less expensive than unenhanced. "Pure gas", no ethanol, probably gives 1-5% better economy.
If I haven't confused you enough, let me know and I'll try again.
Renaissance Honky
Joined: Jun 2016
Posts: 1,083
Likes: 156
From: Mound, MN
