91 or 94 octane gas.

[sk47]

Because you're comparing a 10.7:1 LS engine that is not optimized for 91 to a 12:1 coyote that automatically optimizes timing

It's not relevant

Hello; Again in the Engine Masters episode they stated the engine was optimized for 91 octane. Their concern was the portion of running 87 octane which was why the dyno operator pulled 5 degrees of timing before starting the 87 runs. He then added timing gradually. He also adjusted the air fuel mix in a similar way.
This optimization of the timing & air fuel was also done for the other higher octane fuels if memory serves. I also recall the final timing making maximum power was very nearly the same for all fuels used.
They also included average HP and average torque since peak results might not show enough information.

The engine used a Holly fuel injection system so i imagine had similar knock and other sensors as the Ford Coyote. Likely advance and retard of timing as well.

The programs are a TV series I find on Motor Trend channel 281 on direct TV. I do not know if the shows are on youtube. They tend to use GM and Mopar engines much more than Ford which is frustrating. They have done some Windsor testing but I do not think any Coyote at all.

The best way to test an idea is to change only one parameter at a time. They did not do strictly scientific method testing. I would like to see similar testing using a Coyote.

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[WildHorse]

Hello; Again in the Engine Masters episode they stated the engine was optimized for 91 octane.

Ok.. you need to get outta that LS mindset.
And without seeing the tune, you don't know what they did.

I've seen 514hp on 87 with motortrend using a 6.0 liter.
Look at all envolved to achieve that.

Simple timing changes ain't gonna do that.

 

[sk47]

Ok.. you need to get outta that LS mindset.
And without seeing the tune, you don't know what they did.

I've seen 514hp on 87 with motortrend using a 6.0 liter.
Look at all envolved to achieve that.

Simple timing changes ain't gonna do that.

Hello; Perhaps i see the differences now. The episode happened to be about an LS type V8. I did not pick it because it was an LS. I picked it to review because of the title DOES OCTANE MAKE POWER? It was not a Ford vs. GM thing for my purposes.

The idea, to my mind, is that the energy comes from the gasoline which means a gallon of 87 has the same energy content as a gallon of 91. The testing was to see if the octane of the fuel made power. It (octane) did not as the results of 87, 91, 110 and 116 octane fuels made very close amounts of power. Statistically identical.
Can an engine be set up to take advantage of higher-octane fuels was not exactly the question addressed. We know such can be done. Some 87 designed engines will not make more power no matter the higher octane used.
Some engines that can make more power on higher octane fuels must have that higher octane fuel in order to live when stressed. They will have destructive pre -ignition if run hard on too low an octane fuel.
The Ford Coyote is a complex engine with overhead cams that adjust. Direct injection. Computer sensors that can adjust timing and the cams on the fly and allow it to run on 87 octane fuel with somewhat high mechanical compression, but then also take some advantage of higher-octane fuels. What I have gathered from the thread is 94 octane may be the upper limit at which a Coyote can take advantage. Not at all shabby to be able to run on 87 and 94 in the same engine.

I fumbled the question a few posts back in a post. That the LS in the TV episode did not make use of higher-octane fuels to make significant increases in power was presented poorly. The LS engine is natively set up to run on at least 91 octane. They got it to make similar power on 87 octane by being very careful in a somewhat controlled dyno room environment. They all stated running the engine on the street with 87 would be a mistake.
The engine could not use the increased octane limits of the 110 & 116. Same as an engine designed for 87 cannot use 91 to any advantage.

I have picked learned from this thread and have been able to organize some thoughts.

 

[GL95]

Hello; Perhaps i see the differences now. The episode happened to be about an LS type V8. I did not pick it because it was an LS. I picked it to review because of the title DOES OCTANE MAKE POWER? It was not a Ford vs. GM thing for my purposes.

The idea, to my mind, is that the energy comes from the gasoline which means a gallon of 87 has the same energy content as a gallon of 91. The testing was to see if the octane of the fuel made power. It (octane) did not as the results of 87, 91, 110 and 116 octane fuels made very close amounts of power. Statistically identical.
Can an engine be set up to take advantage of higher-octane fuels was not exactly the question addressed. We know such can be done. Some 87 designed engines will not make more power no matter the higher octane used.
Some engines that can make more power on higher octane fuels must have that higher octane fuel in order to live when stressed. They will have destructive pre -ignition if run hard on too low an octane fuel.
The Ford Coyote is a complex engine with overhead cams that adjust. Direct injection. Computer sensors that can adjust timing and the cams on the fly and allow it to run on 87 octane fuel with somewhat high mechanical compression, but then also take some advantage of higher-octane fuels. What I have gathered from the thread is 94 octane may be the upper limit at which a Coyote can take advantage. Not at all shabby to be able to run on 87 and 94 in the same engine.

I fumbled the question a few posts back in a post. That the LS in the TV episode did not make use of higher-octane fuels to make significant increases in power was presented poorly. The LS engine is natively set up to run on at least 91 octane. They got it to make similar power on 87 octane by being very careful in a somewhat controlled dyno room environment. They all stated running the engine on the street with 87 would be a mistake.
The engine could not use the increased octane limits of the 110 & 116. Same as an engine designed for 87 cannot use 91 to any advantage.

I have picked learned from this thread and have been able to organize some thoughts.

Why do you think people have their cars tuned if there is no advantage to using higher octane?

 

[sk47]

Why do you think people have their cars tuned if there is no advantage to using higher octane?

Hello; your comment does not reflect what I have stated nor what the other information presented implies.
A tune as I have gathered from reading, watching programs and such can affect many functions of an engine. From throttle response to air fuel mixture, timing and likely many other things. From the factory it is likely many parameters are a compromise between, reliability, fuel economy, safety, drivability, emissions and things i do not know about. Setting engine parameters to get maximum HP may reduce both reliability and fuel economy.
My WAG is there can be "tunes" which concentrate on drivability and do not approach using higher octane fuel. Maybe to change the transmission shift points to improve fuel economy as an example. Maybe to sharpen up throttle response. I get a general thing is to improve performance in some way, but does not have to be the case.
An example I know of concerned excessive oil consumption in F-150 pickups. Seems the rings were either not sealing or taking tens of thousands of miles to set in. Ford would "tune" the throttle body motor to not close all the way when coasting down to a stop with your foot off the pedal. The notion was coasting down with the throttle closed created more vacuum which pulled oil past the not yet sealed rings. Found that in a Ford TSB.

But I get your point in that many want a tune to increase HP and or general performance in some ways. The factory is not going to take things to the extreme. They leave a bit of cushion for reasons mentioned above. A "tune" can get things closer to the limits. A non -factory tune can void a warrant. Some of the diesel tuners are now run out of business for excessive emissions from their tunes.

A basic point has to be the car has a basic structure to take advantage of a tune. An engine with low compression ratio likely cannot be tuned to take advantage of higher octane. Maybe get some optimization for running on 87 but no advantage from 91.

In the old days two cars with the same power output from similar engines could have very different performance by having different rear gear ratios. A 3;55 rear end will be sluggish compared to a 3:73 or 4:11.

More to the point. An engine needs some basic mechanical structure (higher compression as example) to be able to take advantage of being tuned for higher octane. If that structure exists, then it can be tuned to take advantage. Much appears to depend upon what the factory left on the table is my take.

 

[WildHorse]

A tune as I have gathered from reading, watching programs and such can affect many functions of an engine. From throttle response to air fuel mixture, timing and likely many other things. From the factory it is likely many parameters are a compromise between, reliability, fuel economy, safety, drivability, emissions and things i do not know about

Ignition timing: optimizing the timing of the spark event to optimize combustion efficiency and power output.

Air/fuel ratio: optimizing the ratio of air to fuel in the combustion chamber to maximize power and fuel efficiency.

Fueling: optimizing the timing and duration of fuel injectors.

MAF: optimizing the Mass Air Flow Sensor curve.

Shift points (automatic transmissions): Optimizing shift points to improve acceleration.

Rev limiter: Raising the engine's rev limit to allow for higher engine speeds and more power.

Notice how many times "optimizing" is used.

None of this affects emissions, reliability or fuel economy.

A basic point has to be the car has a basic structure to take advantage of a tune. An engine with low compression ratio likely cannot be tuned to take advantage of higher octane.

There are to types of compression:
1. Static.
2. Dynamic.

By changing rod ratios and camshaft profiles, one can get stupid high
dynamic compression with a relatively low static compression. Use enough
ignition lead and most definitely will need high octane fuel.

 

[GL95]

Hello; your comment does not reflect what I have stated nor what the other information presented implies.
A tune as I have gathered from reading, watching programs and such can affect many functions of an engine. From throttle response to air fuel mixture, timing and likely many other things. From the factory it is likely many parameters are a compromise between, reliability, fuel economy, safety, drivability, emissions and things i do not know about. Setting engine parameters to get maximum HP may reduce both reliability and fuel economy.
My WAG is there can be "tunes" which concentrate on drivability and do not approach using higher octane fuel. Maybe to change the transmission shift points to improve fuel economy as an example. Maybe to sharpen up throttle response. I get a general thing is to improve performance in some way, but does not have to be the case.
An example I know of concerned excessive oil consumption in F-150 pickups. Seems the rings were either not sealing or taking tens of thousands of miles to set in. Ford would "tune" the throttle body motor to not close all the way when coasting down to a stop with your foot off the pedal. The notion was coasting down with the throttle closed created more vacuum which pulled oil past the not yet sealed rings. Found that in a Ford TSB.

But I get your point in that many want a tune to increase HP and or general performance in some ways. The factory is not going to take things to the extreme. They leave a bit of cushion for reasons mentioned above. A "tune" can get things closer to the limits. A non -factory tune can void a warrant. Some of the diesel tuners are now run out of business for excessive emissions from their tunes.

A basic point has to be the car has a basic structure to take advantage of a tune. An engine with low compression ratio likely cannot be tuned to take advantage of higher octane. Maybe get some optimization for running on 87 but no advantage from 91.

In the old days two cars with the same power output from similar engines could have very different performance by having different rear gear ratios. A 3;55 rear end will be sluggish compared to a 3:73 or 4:11.

More to the point. An engine needs some basic mechanical structure (higher compression as example) to be able to take advantage of being tuned for higher octane. If that structure exists, then it can be tuned to take advantage. Much appears to depend upon what the factory left on the table is my take.

So then the engine can be optimized to use a higher octane

 

[sk47]

gnition timing: optimizing the timing of the spark event to optimize combustion efficiency and power output.

Air/fuel ratio: optimizing the ratio of air to fuel in the combustion chamber to maximize power and fuel efficiency.

Fueling: optimizing the timing and duration of fuel injectors.

MAF: optimizing the Mass Air Flow Sensor curve.

Shift points (automatic transmissions): Optimizing shift points to improve acceleration.

Rev limiter: Raising the engine's rev limit to allow for higher engine speeds and more power.

Notice how many times "optimizing" is used.

None of this affects emissions, reliability or fuel economy.

Hello; I must disagree and do think the list of things made bold can affect fuel economy and reliability for sure and very likely emissions to some degree. Raising the rev limit clearly can affect reliability as well as fuel economy.
Optimizing timing and duration of fuel injectors can go either way in terms of fuel economy. I will figure you mean changed to get more power. Push more fuel and make more power up to the point of running rich.

There are to types of compression:
1. Static.
2. Dynamic.

By changing rod ratios and camshaft profiles, one can get stupid high
dynamic compression with a relatively low static compression.

Hello; I follow you about static vs dynamic compression. I think i have one or two episodes recorded about dyno tests on this subject but will not report unless asked on that after the backlash about the octane program.
Thing is you are talking about serious engine modification changes from factory. If we get into the realm of possible changes of parts such as cams and connecting rods then an engine can be built which can better take advantage of higher-octane fuels. Such is a new and different level beyond stock factory engine parts.

 

[sk47]

So then the engine can be optimized to use a higher octane

Hello; some engines can be "tuned" to take advantage of higher octane while other engines cannot. A Coyote engine and an LS engine appear to be the ones discussed in this thread.

The LS engine happened to be the one used in the dyno testing TV show about octane. Seems it's basic assembly of parts was able to use 91 octane and be able to live in a vehicle used on the street on a regular basis. That the test crew made some runs on 87 and it lived was due to them being very careful in their approach. They even stated running 87 was a risky thing to do and had concerns.
Fuels with octanes above 91 did not make any more power in the LS. Neither the 110 nor the 116 race gas. my take is the engine components did not have any capacity to take advantage of octanes above 91.

It would be nice for this discussion to have a similar set of dyno runs using a stock Coyote with a similar range of octane fuels. Such a reference might answer the questions.

Along the line the discussion got sidetracked and such was my fault. I wanted to make the point that the power comes from the fuel itself. A gallon of 87 octane gasoline has the same amount of energy as a gallon of 93 octane gasoline.
One point being there is no need to pay for higher octane fuel if neither the engine or your driving habits do not take advantage of it. A Mustang GT owner can run on 87 all the time if they do not track the car or say do not drive hard thru Death Valley.

I guess a main point is the question of 87 vs 91 octane in terms of performance. Some say they cannot feel a seat of the pants difference. Others say they can feel a difference.

One post stated 94 octane is the most a factory ford tune will adjust for.

A simple truth is I as an individual do not know for sure. A story I have been getting the last few years is running 87 versus 91 gas will cost something like 8 to 12 HP. Is that peak HP? If so for most of my driving the loss would never be noticed. If the loss happens in the mid RPM range, then i might notice.

Last thing I guess is are you asking if a tune can be had on a Coyote which makes it require 91 octane only? No more ability to run on 87.

 

[K4fxd]

A gallon of 87 octane gasoline has the same amount of energy as a gallon of 93 octane gasoline.

Correct but the 93 octane fuel will run more efficiently in a high compression engine, like the coyote, and be more efficient. It will allow the engine to use more of the energy content to make usable power.

One post stated 94 octane is the most a factory ford tune will adjust for.

94 or 95 is needed to get MBT timing. At least in my area with our shit gas.

A story I have been getting the last few years is running 87 versus 91 gas will cost something like 8 to 12 HP. Is that peak HP? If so for most of my driving the loss would never be noticed.

It's more in the lower end of the rev range, so more area under the curve.

Last thing I guess is are you asking if a tune can be had on a Coyote which makes it require 91 octane only? No more ability to run on 87.

Yes a tune can be made for only 91 or 93, actually it would be 91 or more or 93 or more.

I have a dedicated 100 octane tune. It makes the same top end power as the 93 tune but has a lot more midrange.

 

[sk47]

Correct but the 93 octane fuel will run more efficiently in a high compression engine, like the coyote, and be more efficient. It will allow the engine to use more of the energy content to make usable power.

Hello; Yes to this. Appears I have muddled things up some.

 

[RiotfunK]

I don’t see 94/95 much anymore. I use 93 from usually Sunoco/Shell. Not a fan of Mobil anything.

I find anything boosted from factory or aftermarket as well as anything high revving like the Mustang benefits from it. And will be more noticeable in these types of vehicles for performace, mpg, etc.

I won’t run 91. The price difference is minimal and not worth it to run lower octane fuels.

 

[sk47]

The price difference is minimal and not worth it to run lower octane fuels.

Hello; The price difference between 87 and 91 went up recently in my area. From 50 cent/gal to 70 cents/gallon more for 91.

 

[RiotfunK]

Hello; The price difference between 87 and 91 went up recently in my area. From 50 cent/gal to 70 cents/gallon more for 91.

Same here. The extra few bucks is worth it.

 

[CarmeloS]

I got a Bronco w/a 93 tune. I notice quite a difference with 94, like they threw in an espresso shot or two

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