87 octane vs 93 octane - ECOBOOST

[Gros Ventre]

Compression, advancing the spark, etc...

There is more to it than what you claim. The whole more power thing has been proven with these motors.

That is also why ford recommends 91+ octane when towing heavy loads. You can get 30-50 more torque from the higher octane fuel, which means your vehicle will downshift less when towing thus reducing transmission temps.

I have run both with and without a trailer. You can noticeably tell the difference in both cases, but it is extremely obvious when towing. I just wish the 30% more I pay per gallon for premium gave me 30% more mpg, but nope... it is something about 10-15% when towing... though less time filling up is always welcome. I have also noticed I get about 2-3 more lbs of boost when running 93... refer to my first points as to why that is.

You miss the whole point: an engine is designed for a specific max power with a given intake charge and temperature, compression, fuel injection, spark advance and octane rating. Every thing else is a de-rating from that point. The fact that Ford can use the computer setup to finesse these things is nice, but it doesn't speak to the design point of the engine. Then it doesn't speak to Ford's methodology of ensuring a margin from that point so that anyone driving it a bit too hard doesn't blow the engine up.

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[Angrybeaver]

You miss the whole point: an engine is designed for a specific max power with a given intake charge and temperature, compression, fuel injection, spark advance and octane rating. Every thing else is a de-rating from that point. The fact that Ford can use the computer setup to finesse these things is nice, but it doesn't speak to the design point of the engine. Then it doesn't speak to Ford's methodology of ensuring a margin from that point so that anyone driving it a bit too hard doesn't blow the engine up.

This might be true, but a simple tune can add almost 100/100 gains in these things.

These motors can handle more than they are being sold with.. look at the 3.5 raptors.

So if you are saying they leave the factory tuned for 400/500 at 87 octane I would agree. That tune is likely retarding the spark thanks to things like octane sensors, knock sensors, etc. If high octane gas made no difference they wouldn't recommend it for towing.

 

[Gros Ventre]

This might be true, but a simple tune can add almost 100/100 gains in these things.

These motors can handle more than they are being sold with.. look at the 3.5 raptors.

So if you are saying they leave the factory tuned for 400/500 at 87 octane I would agree. That tune is likely retarding the spark thanks to things like octane sensors, knock sensors, etc. If high octane gas made no difference they wouldn't recommend it for towing.

Oh, they recommend it for towing so that you don't blow up an engine that is off brand new settings and you're overloaded, on a hot day climbing a long, long stretch...

 

[Angrybeaver]

Oh, they recommend it for towing so that you don't blow up an engine that is off brand new settings and you're overloaded, on a hot day climbing a long, long stretch...

How do you propose they "blow it up?"

The only real difference in fuel would be the engine knock that happens. The truck is going to retard the spark to make sure you aren't blowing it up. Heat would likely be a concern on either gas of you are that close to the limit.

Are you saying that that the better knock properties makes enough of a difference that the motor would "blow up" on 87 vs 93... I don't see that being a realistic scenario if your argument revolves around it not adding power. Most vehicles in the last decade can take measures to keep that from happening.

There has been plenty of actual proof from dyno runs that show a performance difference does exist.

 

[Chili]

You miss the whole point: an engine is designed for a specific max power with a given intake charge and temperature, compression, fuel injection, spark advance and octane rating. Every thing else is a de-rating from that point. The fact that Ford can use the computer setup to finesse these things is nice, but it doesn't speak to the design point of the engine. Then it doesn't speak to Ford's methodology of ensuring a margin from that point so that anyone driving it a bit too hard doesn't blow the engine up.

I think the whole point you missed is you are incorrect and you refuse to not only acknowledge it, but also let it go.

Your info and "facts" are incomplete, outdated and not completely relevant to a modern engine.

Good day sir. This ship has sailed and you're still at port.

 

[Gros Ventre]

I think the whole point you missed is you are incorrect and you refuse to not only acknowledge it, but also let it go.

Your info and "facts" are incomplete, outdated and not completely relevant to a modern engine.

Good day sir. This ship has sailed and you're still at port.

It would be nice if you understood some fundamental thermodynamics, but ignorance is bliss...

 

[Snakebitten]

On this particular subject matter I think you will not sway. I admire the tenacity. I just don't agree.

There's now more than a decade of evidence and history to support the claim that Ford created a torque based engine management system to go with the twin turbo 3.5 Ecoboost motor, AND that they purposely flashed the PCM with a considerably conservative strategy for potential power output.

Lot's of safety margin in it.
Incredibly versatile and capable of adjusting its own power producing potential based on multiple parameters. Air density, fuel anti-knock properties, intake air temperature, load,.......

You can leave your driveway in the morning with the truck willing to produce XXX ft lbs of torque at WOT, and then 4 hours later, under different conditions, the truck is willing/able to produce XXY ft lbs of torque at WOT.

Both maximum outputs are within the design parameters of the manufacturer. And some of those influencing properties are at the behest of the driver. Fuel being the most obvious.

 

[JExpedition07]

Are you guys debating with Gros Venture? I can’t see ?

 

[Samson16]

I understand the sentiment, honestly but and I'll get right to the point, there was a long period of corn being too cheap. Unprofitable to grow. It needed the new market.

To important to lose I suppose. Well, ethanol welfare is better than paying not to grow at all. Grumble grumble ? ??‍?

 

[Samson16]

Are you guys debating with Gros Venture? I can’t see ?

I can’t either! I didn’t know he blocked me lol ?

 

[HammaMan]

I can’t either! I didn’t know he blocked me lol ?

I think I was first on his block list. That's okay, emotionally sensitive snowflakes need their world carefully crafted to support their delicate nature.

 

[Chili]

On this particular subject matter I think you will not sway. I admire the tenacity. I just don't agree.

There's now more than a decade of evidence and history to support the claim that Ford created a torque based engine management system to go with the twin turbo 3.5 Ecoboost motor, AND that they purposely flashed the PCM with a considerably conservative strategy for potential power output.

Lot's of safety margin in it.
Incredibly versatile and capable of adjusting its own power producing potential based on multiple parameters. Air density, fuel anti-knock properties, intake air temperature, load,.......

You can leave your driveway in the morning with the truck willing to produce XXX ft lbs of torque at WOT, and then 4 hours later, under different conditions, the truck is willing/able to produce XXY ft lbs of torque at WOT.

Both maximum outputs are within the design parameters of the manufacturer. And some of those influencing properties are at the behest of the driver. Fuel being the most obvious.

Always with the polish and patience others (myself included) lack. Well worded.

 

[Snakebitten]

We get along just fine.
Lot's of Powerboost conversations, on the side. I enjoy the debate too.

But he's not going to budge on this.
I'm cool with that.
I got my un-budging stubborn turf as well. At least my oldest daughter claims as much often.

 

[Gros Ventre]

Attached is the pressure-volume diagram for the Otto Cycle that our engines employ. What is important is Point 2 and 3 on the diagram. Point 2 theoretically represents top dead center or the completion of the compression stroke. The line from 2 to 3 is the burning of fuel. Line 3 to 4 theoretically represents the downstroke or power stroke of the piston. The reality is line 2-3 is the burning of the fuel which takes a measurable amount of time. The purpose of ignition timing advance is to so time things that the combustion is just complete at TDC or a hair after TDC. The purpose of octane is to prevent the fuel from pre-igniting before the spark arrives. That theoretical point #3 is determined by engine design. It presumes certain things like intake charge, sea level pressure or boost pressure, spark advance, and so on. It cannot be changed. The rest of the things like variable valve timing or spark advance or other computer controls improve engine operation by approaching that perfect design point but the basic design determines how the engine operates in light of these variables. When you throw in wear and tear, hot summer days, carbon deposits (that may be glowing), less than advertised octane, a possibly overloaded trailer... using 93 octane is a good idea because it gives you some margin to bad things.

 

[Snakebitten]

Again, I admire the tenacity to defend a position with science, facts, evidence, documentation.........

I don't see anything in the documentation of "the Otto cycle" that difutes the claim that the 3.5 Ecoboost motor, along with its programmed engine management system, creates additional power/torque with 93 octane vs 87.

Unless I am once again misunderstanding the point.

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