91 octane or 87, 2025 BS BL

[Carl 2]

The owners manual for my 2025 BS BL says the motor can operate on unleaded 87 octane although the use of this fuel can damage motor and void warranty. Then the manual says to use 91 octane but beware of engine knock. ????

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[thomasm23]

The owners manual for my 2025 BS BL says the motor can operate on unleaded 87 octane although the use of this fuel can damage motor and void warranty. Then the manual says to use 91 octane but beware of engine knock. ????

You are misquoting the owner’s manual. 87 octane fuel is appropriate to use.

 

[Carl 2]

You are absolutely right, thanks.

 

[RSH]

Yes the owners manual says the vehicle operates on 87 octane fuel. The owners manual also says for best overall performance use 91 or higher octane fuel.
While I do not have a 2025 Badlands, I do have a 2021 Badlands and typically use 91 octane fuel, it doesn't cost that much more and I do notice the difference in how it performs compared to running 87 octane.

Obviously you can choose whatever works for you.

 

[Warped9]

While I do not have a 2025 Badlands, I do have a 2021 Badlands and typically use 91 octane fuel, it doesn't cost that much more and I do notice the difference in how it performs compared to running 87 octane.

Can you elaborate a bit more? What is the difference you see? Does it affect fuel economy for better or worse or not at all?

 

[BLUEOVALRACER]

If you want the 250 Horsepower and 277 lb.ft of Torque that your engine is rated at use 91 octane otherwise you're not getting that much power on 87 octane.

 

[hcrews1955]

I Have a 2025 BS BL Sasq. Now 4th tank of VP fuels 93 octane Non Ethanol and averaging 4-5 mpg increase (25.348 mpg at fill today). I drive off road at low speeds most of the time . Don't need to press the accelerator very much. Paying today at $3.39/gal. Will take the BS to Mooresville's HRGoffroad and leave for a week for a 2 1/2" lift kit install. They want to make sure their kit will fit, adjust as necessary for the Sasquatch package and I get to keep the kit.

 

[SgtT11B]

Yes it runs on 87 but its not optimum. The HP rating Ford issues is with 93, in parts you can only 91 you are already behind the 8 ball. This has been debated to death, and the Ecoboost likes the premium.

 

[Adanac]

I've always used 93 in mine, more getup & go. Both BL, my 21 &23 and my next 26 one.

 

[RSH]

As SgtT11B noted, the engine performance of the Sport is optimized when using 91 or higher octane fuel. It allows the engine to operate at full potential.
Because the engine feels like it runs more spirited you tend to drive more spirited as well.
Will you see a big jump in fuel mileage, not likely.
Though you may see some change.

You can try it yourself, hopefully an extra few dollars for fuel doesn't derail your budget.
If you notice a difference fine and if not, oh well, at least you tried what the owner's manual recommends. Not a big deal either way.

 

[BroncoBoy25]

I have been using 91 octane (highest available here) since I saw a post here about it. I do get better mileage. There is a bigger jump in price from 87 to 89 than 89 to 91, so why not. And I have the 1.5L engine, so any improvements are welcome. I have had it about three months and have an oil change scheduled, to get the initial wear stuff out of it. Make it last a while. I’m getting over 29 MPG right now.

 

[jkernitzki]

From a cost/benefit take, I ran some numbers with interesting results.

YMMV. Literally.

Assumptions:

• Complete fill-ups of 16 gallons
• My local prices today in Metro Phoenix
• Estimated average mpg
• 10,000 miles per year driven
• 2.0L MPC

My main takeaway is 91 would, while costing about 15% more per fill-up, save ~$123 over a year using nearly 30 gallons less than 87 over the same period.

I've attached the spreadsheet so you can do your own comparison.

Octane	Fuel	$/Gal	Cost/Tank	MPG	Range	Cost/mi	10K Mi	Cost Delta	Gallons Delta
87	16	$3.61	$57.76	21.0	336	$0.172	$1,719.05​	$0.00​	0.00
89	16	$3.96	$63.36	23.5	376	$0.169	$1,685.11​	-$33.94​	8.57
91	16	$4.15	$66.40	26.0	416	$0.160	$1,596.15​	-$122.89​	29.61

 

[RSH]

In hot weather climates 91 or higher octane makes a lot of sense, with hot weather the chances of pre-detonation is greater, using higher octane fuel helps to prevent that as well as the associated power loss.

 

[Dude]

….
[/QUOTE]
Good analysis but I personally don’t think there’s much mpg gain using 91 octane .. but overall bottom line probably not much overall net added cost of premium 91 fuel over regular unleaded (I think I’ll do the calculation now to see the savings using 87)

Here’s a pretty good thread on the topic..the link is about 2/3s in on the posts so can back up to read more or skip ahead in the link

https://www.broncosportforum.com/forum/threads/bronco-sport-fuel-milage.12007/post-201529

 

[dockiwi57]

From a cost/benefit take, I ran some numbers with interesting results.

YMMV. Literally.

Assumptions:

• Complete fill-ups of 16 gallons
• My local prices today in Metro Phoenix
• Estimated average mpg
• 10,000 miles per year driven
• 2.0L MPC

My main takeaway is 91 would, while costing about 15% more per fill-up, save ~$123 over a year using nearly 30 gallons less than 87 over the same period.

I've attached the spreadsheet so you can do your own comparison.

Octane	Fuel	$/Gal	Cost/Tank	MPG	Range	Cost/mi	10K Mi	Cost Delta	Gallons Delta
87	16	$3.61	$57.76	21.0	336	$0.172	$1,719.05​	$0.00​	0.00
89	16	$3.96	$63.36	23.5	376	$0.169	$1,685.11​	-$33.94​	8.57
91	16	$4.15	$66.40	26.0	416	$0.160	$1,596.15​	-$122.89​	29.61

That is interesting. Thank you for sharing your data. These numbers, along with the +/- emotionally biased perception of "peppier" performance make a strong argument for the 2.0L MPC. Out west it is not uncommon to see pricey tier 1 ethanol-free premium grades. I've wondered if these preparations reduce, increase, or have no effect on MPG.

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