87 vs 91 Octane?

[Jess1]

"Sure they are, they all do"
Yep. Distributors sell to all brands. There's no separate tank for "exxon", or "shell", or whoever. Additive packs are blended in at different stages...
Some brands will require branded transport, but the product is the same.
FWIW, "leftover" (they don't ship gas back) fuels are sold on the open market, and can even be downgraded (prem to reg).
Not uncommon to find premium branded fuels sold as regular at no name stations...

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[JennyB1977]

This might be a dumb question…I went to get gas the other day and these were my options. Went with 88. I have just over 16k miles on my Big Bend. Is that okay or a mistake?

 

[13MikeH]

Unleaded 88, also known as E15, consists of 15% ethanol and 85% gasoline.

This fuel has a higher octane rating than regular 87 octane fuel, offering your engine a boost, and it burns cleaner than regular unleaded, improving our air quality and reducing greenhouse gas emissions. It is also typically offered at a lower price

The difference is Unleaded 87 has 10% ethanol and Unleaded 88 has 15% ethanol. The 5% increase in ethanol increases the octane rating to 88.

Mild downside, the more ethanol, the more it tends to gum up fuel lines etc over time.
It's easy to say one tank won't be an issue, and with new motors it's less likely to cause harm...I was forced to use 92 octane on a road trip long ago and it fried my oxygen sensors. Again far les.likely with the technology today...but never say never

 

[ZeroCool]

I typically go 89 honestly. The mid grade.

 

[gcbroncosport]

Interesting read and test from Car and Driver on the question. They do test mostly high performance vehicles, but the CRV provides a relevant case study. HP bump was interesting and even more interesting was the slower 0 to 60 on premium!

Ultimately, what the owners manual says

https://www.caranddriver.com/features/a28565486/honda-cr-v-vs-bmw-m5-ford-f-150-dodge-charger/

 

[Rob_Broncowski]

I’ve been running 87 since the day I got it. 1500 miles now roughly. No issues. Still get 27mpg as of now with bigger tires, only driving small distances back road, with a once a week highway run.
Read the owners manual the day I got it and the way I interpreted it was that it was designed to run on 87 but use higher octane for maybe towing type applications. I’m not opposed to putting in premium as every car I’ve ever owned required it, but if it doesn’t say it’s a necessity in the manual, I figured I’d run regular until someone or some study tells me otherwise when it comes to the 1.5l in the bronco.

 

[SLJ]

91 when towing.

 

[Mark S.]

This might be a dumb question…I went to get gas the other day and these were my options. Went with 88. I have just over 16k miles on my Big Bend. Is that okay or a mistake?

Your owner's manual says you must use fuel with a minimum octane of 87 that contains no more than 15% ethanol. As others have noted, the 88 octane selection is 15% ethanol, so it meets both of the manual restrictions. The reason it's 88 octane instead of 87 is because ethanol is higher octane than gasoline. By upping the ethanol content to 15% in this blend you get slight higher octane than the 87 octane regular, which is most likely 10% ethanol.

The only major downside to using fuel with 15% ethanol is your fuel economy may suffer. Ethanol has much less energy content (measured by BTUs) than gasoline, so increasing the ethanol content in a blend will reduce the overall amount of energy in each gallon.

 

[jkbronco]

I use 93 premiunm on ours. the last 2 trips we went out i switched to 93 and noticed a huge differenece in pulling our trailer and performance and MPG's. For what is is worth the premium does help with adjusting the timing and hp for the mountains. Just my 2 cents.

 

[AiricTheRED]

Ran 87 for the first few weeks. Between pay days(every 2 weeks) I used 1.5tanks of fuel.
Switched to 91, I now use 3/4 of a tank every 2 weeks. Driving has not changed, if anything I go further now with nicer weather.
Worth it to run higher octane 100%

 

[fpizzo80]

Why would anyone think a higher anti knock formula fuel would be beneficial ?
My 1.5 doesn't knock or ping at all, the engine is designed to run on 87 so why defeat the monetary savings of the 26 mpg with a far more expensive fuel ?

i HAVE A 22 OUTER BANKS and by using the 91 octane i get 28 -32 mpg. Rus better on the 91 as well.

 

[Mark S.]

Ran 87 for the first few weeks. Between pay days(every 2 weeks) I used 1.5tanks of fuel.
Switched to 91, I now use 3/4 of a tank every 2 weeks. Driving has not changed, if anything I go further now with nicer weather.
Worth it to run higher octane 100%

You're almost certainly getting better mileage because of the warmer weather, not because of the higher octane. I encourage you to do some testing. Track mileage manually over a minimum of three tanks (as recommended by the Owner's Manual) under the same driving conditions (city/highway mix, similar ambient temps, etc.) for both regular and premium. My testing revealed no significant economy improvement with premium.

https://www.broncosportforum.com/forum/threads/2-0l-mpg-fuel-mileage.4723/page-6#post-98111

 

[M3H7363]

Ran 87 for the first few weeks. Between pay days(every 2 weeks) I used 1.5tanks of fuel.
Switched to 91, I now use 3/4 of a tank every 2 weeks. Driving has not changed, if anything I go further now with nicer weather.
Worth it to run higher octane 100%

Think about what you are claiming here.

1.5 tanks of fuel for 2 weeks with 87 octane
3/4 tank of fuel for 2 weeks with 91 octane

That is half as much fuel or double the mileage, however you want to look at it. Impossible.

If that were anywhere near the realm of being possible, everyone would use 91. Nowhere near being realistic.

 

[Osco]

Two weeks with a head wind,
Two weeks with a tail wind,
Happens to me now and then.
As for 1.5 tanks then 3/4 tank umm that’s double the mileage.
It’s like when Is a fish the biggest ?
After It’s caught.
I call bull hockey on that one
Just sayin~~~~

 

[AmazingSieve]

You're almost certainly getting better mileage because of the warmer weather, not because of the higher octane. I encourage you to do some testing. Track mileage manually over a minimum of three tanks (as recommended by the Owner's Manual) under the same driving conditions (city/highway mix, similar ambient temps, etc.) for both regular and premium. My testing revealed no significant economy improvement with premium.

https://www.broncosportforum.com/forum/threads/2-0l-mpg-fuel-mileage.4723/page-6#post-98111

Might not improve mpg, but I’m convinced it sounds better on 91 vs 87.

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