Gasoline octane & MPG

[buckingup]

So, I've been getting shockingly bad gas mileage. I've put 1700 miles on my BD in a couple of weeks. averaging 15.5 mpg..... but thats including different drive modes.
Anyway, today, I filled her up with 89 octane, instead of 87, and over 50 miles, (most of it highway), I averaged 20 MPG.
In my old FJ cruiser, I had found that higher Octane gas, especially on highway trips, made a big difference in terms of better mileage. However as the vehicle got older, it seemed like the lower octane fuels were causing problems, even though the FJ was supposed to handle multiple octane fuels.
I dont know anything about what's considered the best fuel to use in the 2.3 engine.?

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[MNBigfoot]

20% gain in MPG with 2% difference in octane, now that's impressive, dam near unbelievable.

 

[buckingup]

20% gain in MPG with 2% difference in octane, now that's impressive, dam near unbelievable.

Agreed and not a reasonable amount of miles to call it definitive. I also reset my MPG just before trying it with the higher octane gas, so there are lot's of variables. I'lll give it a few hundred miles and see where I go. I was rather shocked at what a gas guzzler this Bronco is. So I have to say, this is more hopeful than believable. I did read some post on here with some people mentioning MPG above 17. With that being said, I did experience much much better MPG with premium. with the FJ. So much so, that the difference in cost was completely worth it.

 

[RagnarKon]

The MOST you can expect from running higher octane is 3% improved MPG—and that is only if that premium fuel is ethanol free. Premium fuel is almost always 3% more expensive than 87, so it you are looking at it from an economics standpoint it is almost always cheaper to run 87.

Any difference you've seen beyond 3% has to do with driving conditions/style.

Personally around town I get about 16.5 MPG. On the highway I can get up to 23 MPG—particularly on the flat-and-boring Ohio Turnpike. Towing I get around 14.1 MPG.

 

[RoverDude]

What's the ethanol percentage that you're putting in.
You will get significant increase by using non-ethanol gas. Depending on where you live that may not be available.

 

[RHeinz]

Agreed and not a reasonable amount of miles to call it definitive. I also reset my MPG just before trying it with the higher octane gas, so there are lot's of variables. I'lll give it a few hundred miles and see where I go. I was rather shocked at what a gas guzzler this Bronco is. So I have to say, this is more hopeful than believable. I did read some post on here with some people mentioning MPG above 17. With that being said, I did experience much much better MPG with premium. with the FJ. So much so, that the difference in cost was completely worth it.

The Bronco is not a gas guzzler per say… It’s your foot.

 

[HighVelocity]

Taking a dump at every fillup will net you +1MPG. This is an undisputable fact and anyone who argues is constipated.

 

[Brian_B]

Wasn't someone showing some crazy differences in fuel economy between standard E10 and E0? It was in this same ballpark if I recall. Their Bronco really did not like E0 at all, despite the octane rating being identical, which surprised me and a few other people.

 

[CarlSpackler]

Taking a dump at every fillup will net you +1MPG. This is an undisputable fact and anyone who argues is constipated.

What if you shit your pants since you have the MGV interior?

 

[hilmar2k]

Wasn't someone showing some crazy differences in fuel economy between standard E10 and E0? It was in this same ballpark if I recall. Their Bronco really did not like E0 at all, despite the octane rating being identical, which surprised me and a few other people.

Ethanol has about 70% of the energy of gasoline by volume, so E10 has about 97% the energy of E0. So a 3% increase in mileage seems possible.

 

[Brian_B]

Ethanol has about 70% of the energy of gasoline by volume, so E10 has about 97% the energy of E0. So a 3% increase in mileage seems possible.

Well, they were posting like 15mpg with e0 and 20mpg with E10, so it was a lot more than 3% difference you would expect. And ... if E10 is 97% of the energy, you would expect the opposite - E0 to be ~better~ MPG, since it has more energy per volume.

*EDIT* found the thread
https://www.bronco6g.com/forum/threads/e0-fuel-gets-worse-fuel-economy-in-the-2-7l-bronco.97937/

 

[RoverDude]

Wasn't someone showing some crazy differences in fuel economy between standard E10 and E0? It was in this same ballpark if I recall. Their Bronco really did not like E0 at all, despite the octane rating being identical, which surprised me and a few other people.

I can get non- ethanol gas when I get into rural counties.
I get about 10 to 15% better mpg.

 

[hilmar2k]

I can get non- ethanol gas when I get into rural counties.
I get about 10 to 15% better mpg.

Very unlikely that all came from E0...

 

[Brian_B]

I can get non- ethanol gas when I get into rural counties.
I get about 10 to 15% better mpg.

Well that is interesting too - since you wouldn't expect it to be significant. 3% of so, as has been stated.

 

[Kevin Scarbel]

Agreed and not a reasonable amount of miles to call it definitive. I also reset my MPG just before trying it with the higher octane gas, so there are lot's of variables. I'lll give it a few hundred miles and see where I go. I was rather shocked at what a gas guzzler this Bronco is. So I have to say, this is more hopeful than believable. I did read some post on here with some people mentioning MPG above 17. With that being said, I did experience much much better MPG with premium. with the FJ. So much so, that the difference in cost was completely worth it.

My SAS-spec Broncos all have the 2.3L. I've never gotten less than 18mpg, and that's with 87.
My 2-door averages 20mpg local and 22mpg highway. My 4-door averages 19-20mpg local and 20-21mpg highway.
I started out using 87. Performance was fine, but I now use 91. I do believe 89 is adequate, reasonably better than the lower quality 87.
My MPG numbers are from the instrument cluster.
Per Ford, I maintain 39psi in my LT315/70R17 Goodyear Territory MT tires.

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