Does 5.0 coyote performance improve with octane?

[Bikeman315]

Octane rating is not a rating of power, it is a numerical expression of a gasoline's resistance to pre-detonation, or "pinging"

As you get higher cylinder pressures lower octane fuels will light off before the spark starts the burn, and that does really bad things to rods, bearings and even crankshafts.

Knock sensors will tell the ECU to pull timing out of the curve to reduce cylinder pressures and temperatures when you drive in such a way that causes pinging.

You are not getting any additional power because out of the fuel if you burn 93, what you are getting is the computer being allowed to add the maximum amount of timing the tune will allow, and that equates to torque and HP

A gallon of 87 octane gas has (within experimental error) the same amount of energy, measured in British Thermal Units (BTU's) as a higher octane fuel

Even if you fed it a steady diet of 100 0ctane fuel, the computer is limited by the tune as to how much timing and fuel it can provide.

This is a function of a lot of things, but the biggest one, besides keeping the rotating assembly from self destructing is complying with EPA EU and other government entities emissions limits. Letting the timing advance even if you had the fuel to resist pinging increases NOx emissions.

What are the real world effects of what gas you put in your car?

You really want to use a "Tier 1" or "Top Tier" gasoline that has an additive package that keeps the intake valves clean. You'll loose more HP from crudded up valves than lower octane fuel IMHO. Running a bottle of Techron in the gas a couple of times a year doesn't hurt either.

Thank you! This is the definitive post that should be the response to every octane thread on this forum.

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[Bikeman315]

It is my understanding that the GT's V8 has 12:1 compression ratio. That fact alone, should tell any motorhead that higher octane equals better performance.

That‘s old school thinking. Today’s high compression engines compensate via software. Also read post 15. Octane in itself does not necessarily equal better performance.

If I could buy 100 octane pump gas, I would!

And you would be wasting your money. See post #15.

 

[Germansheperd]

Has anyone done instrumented tests of acceleration and economy with 91 octane vs 87 octane on an unmolested coyote engine? My experience is that you do not gain anything using fuel of higher octane than recommended by the manufacturer.

1- Does Coyote 5.0 performance improve with octane? Absolutely not!
2- Running a quality premium or additives will ensure you get everything Ford gave you.

 

[rijndael]

A while back VMP did some dyno testing that showed a ~20 horsepower difference between 87 and 93.

 

[Neggytive]

A while back VMP did some dyno testing that showed a ~20 horsepower difference between 87 and 93.

I would love to see a data log for the ignition timing on those pulls

 

[robvas]

That‘s old school thinking. Today’s high compression engines compensate via software. Also read post 15. Octane in itself does not necessarily equal better performance.

And you would be wasting your money. See post #15.

100 octane would gain power on a gen 4 Coyote as it would still add timing past what it would get on 93. E30 is what, 96-98 octane depending on who you ask? It gains power as well.

Now, is it worth the high price of whatever 100 octane is in your area (it's double the price of 93 here), for a measly 10-15hp?

 

[Bikeman315]

A while back VMP did some dyno testing that showed a ~20 horsepower difference between 87 and 93.

There has always been a HP loss between 87 & 93 which is why Ford quotes all performance specs using 93. I recall the original numbers for Gen 2 were 10-15HP. The difference is a lot larger on the Ecoboost.

 

[robvas]

Here's some well-known charts, one is a gen 1 coyote and the other is an eco

 

[Sinthor 5.56]

Use 93+ top tier fuel

Just wish more places would carry 93 octane. Here in Arizona it is RARE. A few places that have it....all of them at least an hour away from me on the complete opposite side of the city, unfortunately. Then again, looking at products like Boostane...they do legit claim to be able to turn your 91 into 93 or 94..... Haven't tried that yet. Even when I do, not sure I'll notice a difference between that and "plain" old 91 octane gas.

 

[robvas]

Just wish more places would carry 93 octane. Here in Arizona it is RARE. A few places that have it....all of them at least an hour away from me on the complete opposite side of the city, unfortunately. Then again, looking at products like Boostane...they do legit claim to be able to turn your 91 into 93 or 94..... Haven't tried that yet. Even when I do, not sure I'll notice a difference between that and "plain" old 91 octane gas.

Half a can of Boostane will turn your 93 into 100....and coat everything orange in the process!

 

[Sinthor 5.56]

Half a can of Boostane will turn your 93 into 100....and cost everything orange in the process!

Sorry, not sure what you mean by "coat everything orange?"

 

[CRC123]

With compression ratio of 12:1 mine will live on 93 here in Michigan

 

[AZ_Ryan]

Sorry, not sure what you mean by "cost everything orange?"

I was wondering the same thing.

 

[robvas]

I was wondering the same thing.

coat

 

[AZ_Ryan]

coat

Ahhhh

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