Will 94 octane provide more HP than 91 octane?

raqball

Most of the places where I saw the 85 octane was at truck stops along I84 and I80..

I suppose it could have been rec gas but not sure why they'd offer it at truck stop places like Loves, Flying J, TS etc.. Think I even saw it at a Kum & Go off I80 (WTF is up with that name - LOL)

Utah has 85 at most of it's gas stations. I'm not 100% sure on Southern Utah, but Northern Utah 100% has it at all stations.

the poacher

Hi all,
I have tried to research this question and I have not been able to find a definitive answer. I am hoping that one of you will know the true answer to my question, and that is:
The Bronco will increase it's 2.3l engine's horsepower to 300hp if you run 91 octane rather than 87. 91 octane is what Ford considers to be Premium fuel.
Will the engine increase it's horsepower beyond 300hp if you run 94 octane (this octane is available in British Columbia)? If so, does anyone know by how much?
I look forward to any insights that you may have.
Thanks!

Here's why the answer is "no":

The engine ECU is able to adapt to varying octane levels. But it basically works backward. For lower octane levels, timing can be retarded to avoid knocking. But timing can't be advanced past the optimal tune settings Ford has programmed. There's a maximum compression ratio that the engine can handle. Likely, that is what Ford programmed for 91 octane. So, simply using higher octane than 91 won't increase power. However, in theory, an after-market tune could bypass those limits, but at the cost of lower reliability.

Polaris425

I thought all 85 was E-85, which you're not supposed to run in the Bronco. High Ethanol content.

85 octane fuel is not the same as E-85. 85 octane fuel is simply a lower octane made available in higher altitudes. This is because at higher altitudes, the air is thinner, so less fuel and lower octane is needed for a clean burn. This also means engines make less power at altitude.

85 octane fuel may contain ethanol, but only up to 10%. Most fuel distributed in the U.S. contains 10% ethanol, particularly in colder climates during the colder months (approximately mid-October through mid-March). Some gas stations offer ethanol-free fuel, which is generally a good idea to use with small engines (lawn mowers, etc.) E-85 fuel is up to 85% ethanol, which likely won't ever be found in an octane as low as 85 due to ethanol's higher octane content compared to gasoline.

the poacher

Hi all,
I have tried to research this question and I have not been able to find a definitive answer. I am hoping that one of you will know the true answer to my question, and that is:
The Bronco will increase it's 2.3l engine's horsepower to 300hp if you run 91 octane rather than 87. 91 octane is what Ford considers to be Premium fuel.
Will the engine increase it's horsepower beyond 300hp if you run 94 octane (this octane is available in British Columbia)? If so, does anyone know by how much?
I look forward to any insights that you may have.
Thanks!

We just got back from a 10,000 mile trip out west to see the National Parks, State Parks, National Monuments, and anything else we could squeeze in. We only use Top Tier gas in our Bronco. Out west we noticed it was Sinclair, Conoco, Chevron,and Valero which the last 2 we have in the keys. We used mid grade.

timhood

Here's why the answer is "no":

The engine ECU is able to adapt to varying octane levels. But it basically works backward. For lower octane levels, timing can be retarded to avoid knocking. But timing can't be advanced past the optimal tune settings Ford has programmed. There's a maximum compression ratio that the engine can handle. Likely, that is what Ford programmed for 91 octane. So, simply using higher octane than 91 won't increase power. However, in theory, an after-market tune could bypass those limits, but at the cost of lower reliability.

I guess Ford must be wrong…

https://fordauthority.com/2021/05/2...f 270 horsepower and 310 pound-feet of torque

extra toasty

I guess Ford must be wrong…

https://fordauthority.com/2021/05/2...f 270 horsepower and 310 pound-feet of

I don't pretend to know anything about the car engines today. I had a 1970 Boss 302 when I was younger. I could work on that if it was a minor issue. I remember Premium gas octane being 98-102. But today I don't have a clue with these engines.

All I know is my cars ran better with good gas and higher octane. I figured the Badlands is an expensive truck and I am going to use Top Tier gas for it. Seeing that you do understand these engines today what do you think is a better octane for the Bronco? Thank you.

gypsystarr

I don't pretend to know anything about the car engines today. I had a 1970 Boss 302 when I was younger. I could work on that if it was a minor issue. I remember Premium gas octane being 98-102. But today I don't have a clue with these engines.

All I know is my cars ran better with good gas and higher octane. I figured the Badlands is an expensive truck and I am going to use Top Tier gas for it. Seeing that you do understand these engines today what do you think is a better octane for the Bronco? Thank you.

That’s easy. If you want more power and the extra additives for a cleaner burn, then top tier 93 octane just like Ford used for their Bronco enhanced hp test. Again I run Shell 93 in my two sports cars and my 2.7 Bronco. It’s readily available to me anyway.
I have read from multiple sources (if that means anything) that their gas is top notch.
Turbo’s really love high octane. Especially important is 93 or higher prevents against detonation that’s very damaging to your engine.

I had my Ford dealer install the "Ford Performance ProCal High Performance Program" in my 2.3 Bronco. Per the written copy that came with the programmer, and in my speaking with a Ford Performance Tech, 93 octane gas is required to reach the promised 330 hp and, since I also installed a larger air box & filter in addition to a 3" cat back, using 93 octane is a no brainer for me. I always run ethanol free when I can find it. I am happy.

I have only ever run 91 on both of my Broncos. I do find that 93 makes the engine peppier. I am looking forward to the ProCal as above and I would think 93 would be better. I had a Mustang GT and put a super charger in it. 750 HP. 91 was the minimum and 93 or more even better.

Hard to find 93 in rural areas.

extra toasty

That’s easy. If you want more power and the extra additives for a cleaner burn, then top tier 93 octane just like Ford used for their Bronco enhanced hp test. Again I run Shell 93 in my two sports cars and my 2.7 Bronco. It’s readily available to me anyway.
I have read from multiple sources (if that means anything) that their gas is top notch.
Turbo’s really love high octane. Especially important is 93 or higher prevents against detonation that’s very damaging to your engine.

Thank you I appreciate it. That's good to know about Shell it gives me more options.

extra toasty

I guess Ford must be wrong…

https://fordauthority.com/2021/05/2...f 270 horsepower and 310 pound-feet of torque

Perhaps Ford Authority is wrong. From the 2022 owners manual (pg. 167):

"Your vehicle operates on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.

Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87. The use of these fuels
could result in engine damage that will not be covered by the vehicle Warranty.

For best overall vehicle and engine
performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer. See Towing a Trailer (page 283)."

Eninty

Perhaps Ford Authority is wrong. From the 2022 owners manual (pg. 167):

"Your vehicle operates on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.

Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87. The use of these fuels
could result in engine damage that will not be covered by the vehicle Warranty.

For best overall vehicle and engine
performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer. See Towing a Trailer (page 283)."

Yah maybe you should challenge Car and Driver along with Ford Authority for their findings. After that you can challenge the oil industry for producing a grade of fuel that does absolutely nothing, without any benefits. Then you should challenge Ford for recommending 91 or “higher” fuel for the Bronco.

Then you can challenge AI 🤖.
AI Overview+5
The main difference between 91 and 93 octane gas is that 93 octane gas has a higher octane rating, which means it can withstand more compression before detonating: Octane rating The octane rating of a fuel measures its ability to resist compression in an engine without causing knocking. Higher octane fuels are more stable and can withstand more compression before detonating. Performance Premium 93 octane gas can improve performance and fuel efficiency, and help your engine last longer. Engine knock Premium gas is more resistant to engine knock, which happens when the fuel-air mixture ignites before the spark plug. This is especially beneficial for luxury and performance vehicles with high-compression engines or turbochargers.

@timhood provided the correct answer, as did I but in less detail. The ECU is mapped to deliver horsepower and torque at levels tied to a sensed octane level of the fuel. The Bronco owners manual, published by the manufacturer states the minimum fuel octane rating is 87 and the minimum octane to achieve the best performance (i.e. max engine power) is 91. The OP's question is, is there a power increase between 91 and 94 octane. No one in this thread has provided data that show there is a HP/TQ increase between 91 and 94 octane. There is no debate regarding the power increase from 87 to 91 octane especially since the manufacturer publishes such technical information.

All I know is my car reacts a ton better on 94, period

Eninty

@timhood provided the correct answer, as did I but in less detail. The ECU is mapped to deliver horsepower and torque at levels tied to a sensed octane level of the fuel. The Bronco owners manual, published by the manufacturer states the minimum fuel octane rating is 87 and the minimum octane to achieve the best performance (i.e. max engine power) is 91. The OP's question is, is there a power increase between 91 and 94 octane. No one in this thread has provided data that show there is a HP/TQ increase between 91 and 94 octane. There is no debate regarding the power increase from 87 to 91 octane especially since the manufacturer publishes such technical information.

Every EcoBoost engine has the “OAR”. I know some people won’t understand/accept. That’s fine.

Ford Tuning - What is the Octane Adjustment Ratio?
Last Modified : Aug 16, 2023
We have all seen the people talk about premium fuel as if its worthless additional cost that has no benefits, while others are conned into thinking adding premium fuel to a economy engine is going to result in a cleaner injectors and more power. The truth is that premium fuel definately can contribute to increased power, both with aftermarket and factory tunes. Ford has chosen to deal with this with something called the octane adjustment ratio.What is the octane adjustment ratio on a Ford PCM?The octane adjustment ratio (OAR) is a strategy that the PCM incorporates to adjust for octane level of the fuel used. This is a parameter that can be pulled up with the usage of a scan tool. If you don't have access to a fancy scan tool, give this a try FORScan - The cheapest and best scan tool for Ford DIY Mechanics or use something like HpTuners. Sometimes it can be found under a few different PID names such as Infered Octane, Octane_Ratio, or OAR. The values can also be displayed as a simple digit like 87 or 91, or it will be displayed as its true value -1.0 to 1.0.The simple digit explanation is easy to understand. Your scan tool is interpreting the actual value as either 87 or 91.The actual value that has been calculated by the PCM is a little more confusing to read. An OAR of -1.0 is actually when the engine is at maximum octane adjustment and generally is only realized on Premium 93 Octane gasoline. An OAR of 1.0 is when the PCM recognizes the fuel is of minimum octane recommended by Ford which is Regular 87 gasoline.Why is the octane adjustment ratio backwards?The OAR seems backwards because you must understand how the PCM is making the calculations. The factory tune is comprised of several different spark tables. For example, maximum brake torque (MBT) spark table is your maximum spark allowed, the borderline knock spark table is maximum spark achievable before spark knock occurs in perfect conditions.There are then so many modifier tables such as intake temp spark modifier, variable cam position spark modifier, and of course the octane adjustment ratio that are futher used for calculating spark. These modifiers all work together for the PCM to dynamically come up with a spark value.The octane adjustment reference table is a negative number that is ADDED to the total spark output. So the OAR is a negative number when higher octane is used so that when multiplied the two negative numbers when become a positive number which is ADDED to total spark output.How does the car know if I filled up on premium 93 gasoline?In short, it does not know for certain. The strategy is constantly adjusting to signals from the knock sensor. The OAR is slowly subtracted from to reach a normalized base of -1.0. When the knock sensors detect spark knock, it reverses and starts adding to the OAR. The amount of knock determines the speed at which the ratio is added to.When the knock sensor detects spark knock, the PCM immediately enacts a spark retard table based on the strength of the knock. It quickly removes advance from the spark until the knock no longer happens. The PCM will always push the boundries of the fuel to keep the spark advanced pegged at the furthest forward advance that leads to no knock, and adjust it when knock is detected. Premium 93 Fuel Advantages: The 93 octane rating of the premium fuel allows higher resistance to ignition at higher cylinder temperatures. Higher cylinder temperatures occur when higher compression ratios are used or other power adders like turbochargers or superchargers. This resistance to ignition is avoiding uncontrolled pre-ignition of the fuel called spark knock.On a 3.5L Ecoboost in a Ford F150, using premium fuel can result in an estimated 10% increase in fuel miles per gallon and a similar increase in horsepower. The extra efficency gained is almost exclusively from reduction of spark retard. The increased efficiency doesn't make up the cost difference but every horsepower counts.

timhood

Here's why the answer is "no":

The engine ECU is able to adapt to varying octane levels. But it basically works backward. For lower octane levels, timing can be retarded to avoid knocking. But timing can't be advanced past the optimal tune settings Ford has programmed. There's a maximum compression ratio that the engine can handle. Likely, that is what Ford programmed for 91 octane. So, simply using higher octane than 91 won't increase power. However, in theory, an after-market tune could bypass those limits, but at the cost of lower reliability.

91 octane is “Mid grade to the Ecoboost”

The Ford solution is called an Octane Adjust Ratio (OAR) and the strategy controls access to three distinct load (think boost) limiting tables which we can for the sake of discussion call Low (93), medium (95) and high (97) octane tables.

95 RON = 91 octane

Hey all, just want to thank you for your input. It is always great to read what so many have to say on s particular topic, and that is what makes this forum so enjoyable to follow and to participate in.
Though I still don't have a clear answer to my question, as it would appear that there is no set facts to back up the two positions that have taken place in this thread. I believe that I will stop using 94 octane and continue to run 91 until I can get a definitive answer as to whether it is worthwhile or not. Thanks all!

the poacher

Hey all, just want to thank you for your input. It is always great to read what so many have to say on s particular topic, and that is what makes this forum so enjoyable to follow and to participate in.
Though I still don't have a clear answer to my question, as it would appear that there is no set facts to back up the two positions that have taken place in this thread. I believe that I will stop using 94 octane and continue to run 91 until I can get a definitive answer as to whether it is worthwhile or not. Thanks all!

One more time.
I guess if a person reads this they will understand some of the benefits of running fuel higher than 91 octane in a EcoBoost engine. I understand some folks could care less about maximum performance, but many do.
https://www.motorsport-developments.co.uk/Understanding-Ford-Ecoboost-OAR-Systems.html

Lower octane gas has a marginally higher energy density than higher octane gas. Everything being equal, lower octane will give you better mileage and higher horsepower. BUT, everything isn't equal. Engines designed for higher octane fuel have different timing and higher compression so they're more efficient. But you need higher octane to take advantage of the timing and compression. So engine efficiency increases quicker than fuel energy density decreases.

Ford designed the Bronco engines to run on 87-93 octane. Using higher than 93 octane won't do anything for you if the engine isn't designed for it. It will just cost you more money.

extra toasty

I guess Ford must be wrong…

https://fordauthority.com/2021/05/2...f 270 horsepower and 310 pound-feet of torque

No, Ford Authority simply mangled the information they reported. First, ironically, that article references back to specs published here on Bronco Nation. Second, Ford Authority incorrectly states the power numbers are for 93 octane (probably because that is the octane rating for premium fuel where they are located). Ford Motor Company never references 93 octane, only "91 or higher." The power numbers that Ford Authority reported are achievable with 91 octane.