What Octane Fuel?

[Hack]

What about using pure gas instead of 10% ethanol, what would I gain? I looked up pure gas in my area and most are un-branded and sold thru little mom and pop outlets so I'm worried about quality.

You will get better fuel economy with pure gasoline.

One good thing about ethanol is that the alcohol and water can mix, so ethanol serves as an antifreeze to prevent ice chunks from building up and blocking the fuel going through the lines. You don't care about this in your part of the country, but here where we regularly get down to double digits below zero it is nice to have a little ethanol in the fuel.

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[Highwayman]

California-tastic 91.

Exactly! So jealous of other states.

Not sure I'd run an EB without Premium, but was curious about with the GT. Looks like its not worth it without mods.

 

[stulaw11]

I'm still on my 1st tank and the dealership put in 89 in my stock GT for now. With a tune obviously not though.

Too much price difference in gas for 4HP right now. Regular can be had around here for about $2.30-2.45ish average right now, and premium goes from $2.80-well over $3. The extra $8 per fillup ($.50 per gallon) isn't worth the 4HP loss

I'll probably be sticking with regular as 89 probably wouldnt see any noticeable difference either if premium to regular gas is only a 1%/4HP loss.

 

[POOPonYOU]

Dude, do a search. How many times do we have to answer (and rehash) the same questions?

It's your choice to answer the question or ignore it. Ignore it if you find it annoying. It took you just as much effort to complain about his question instead of just answering it. Just saying. I totally understand your frustration but we're here to help each other not make these forums difficult for newer members.

 

[89Trooper]

Im running 87 in my stock GT for now. With a tune obviously not though.

Exactly this.

 

[Qwkynuf]

87 is fine for all 3 engines (V6, EB, GT).

Using 87:
The V6 takes no HP hit.
The EB takes about a 29-30'ish HP hit (something like 13% loss of HP).
The GT takes about a 1% HP hit

Is this actually documented anywhere? I have seen it repeated over and over in these forums since well before the car was ever released, but I have never seen it published anywhere.

Thanks!

 

[souprmage]

I've had nothing but 92 in mine since new, I even drove it to the dealer's card lock and he filled it up with premium for me.

 

[Jason Richardson]

Non ethanol 92 premium always. Even better now with low gas prices (relatively). Another user of puregas here. Great resource.

 

[Spartan]

Is this actually documented anywhere? I have seen it repeated over and over in these forums since well before the car was ever released, but I have never seen it published anywhere.

Thanks!

They are taken from various reviews of the Mustang, articles, videos, etc.

EB with 87

"Ford is quick to point out that those power figures are gleaned from running 93 octane, which I don't get out in California (stuck with 91-octane piss fuel), but according to an engineer I was grilling, the Ecoboost can run on 87 octane "all day long", while losing 13 percent of its power, but retaining its peak torque."
​

http://jalopnik.com/we-drove-the-2015-ford-mustang-its-still-best-with-a-v-1636142850

If you are on the Ford site, the V6 is the only one with no * next to it's HP/TQ figures which means it's rated off of 87.

 

[analogman]

89Trooper, I absolutely love your comment, "I'm good with 430.65 hp".

I agree completely! My butt can't tell a 1% difference between 435 and 430.65 hp, and I doubt a 1% difference would even show up in a timed test on a track. Air temperature, humidity, tire pressure, and other variables would probably make more of a difference. I don't drive on a track, I drive on the street, and I drive like a sane person, not a maniac. I'm very happy paying 10% less for 87 vs. 93 and not feeling any difference in performance.

High-octane gas has been one of the most successful marketing campaigns, and scams, perpetrated on the American public in decades. I remember the TV commercials with the guy pulling into the gas station and saying, "give me the good stuff". We're all victims of repetitive advertising and media campaigns, and it's been ingrained in all of us that "premium" gas is "better". Even the name, "premium", was conjured to help foster this illusion.

But, it's just not true. High octane fuel is absolutely needed in high compression engines to mitigate detonation. But, it's wasted money otherwise. As a (former) chemist, 87 octane actually has more 'energy' per unit of fuel than 93 octane. There are more carbon-carbon bonds available to be broken and thus more energy to be had. This is lost in a high compression engine which will retard spark if knock is sensed, hence 'high octane' fuel delivers more power and performance - but only in a high compression or turbo motor (like the EB). But, for the majority of engines the majority of the time, it's just pouring money into Exxon-Mobil's pockets and giving their CEO an even bigger bonus. He makes a lot more money than I do, I'll keep the money for myself thank you.

So, if you're tracking the car, or have modified it, and are pushing the engine to the very limits of its capabilities, use 93 octane to reduce the risk of detonation. But, if you're driving on the street like a normal person, save the money for yourself instead of adding to the oil companies profits.

 

[YellowMenace]

m.ford.com/cars/mustang/specifications/
Read detailed 2015 Ford Mustang exterior, interior, engine, specifications & more .


I hate to interject facts but it looks to me like Ford recommends premium for the GT.

 

[cush]

Use whatever octane rating = premium in your neck of the woods, 91 in Colorado.

 

[Asharus]

m.ford.com/cars/mustang/specifications/
Read detailed 2015 Ford Mustang exterior, interior, engine, specifications & more .


I hate to interject facts but it looks to me like Ford recommends premium for the GT.

i would never go by whatever some guy decided to type into a field on a website over what it says in the manual

 

[souprmage]

89Trooper, I absolutely love your comment, "I'm good with 430.65 hp".

I agree completely! My butt can't tell a 1% difference between 435 and 430.65 hp, and I doubt a 1% difference would even show up in a timed test on a track. Air temperature, humidity, tire pressure, and other variables would probably make more of a difference. I don't drive on a track, I drive on the street, and I drive like a sane person, not a maniac. I'm very happy paying 10% less for 87 vs. 93 and not feeling any difference in performance.

High-octane gas has been one of the most successful marketing campaigns, and scams, perpetrated on the American public in decades. I remember the TV commercials with the guy pulling into the gas station and saying, "give me the good stuff". We're all victims of repetitive advertising and media campaigns, and it's been ingrained in all of us that "premium" gas is "better". Even the name, "premium", was conjured to help foster this illusion.

But, it's just not true. High octane fuel is absolutely needed in high compression engines to mitigate detonation. But, it's wasted money otherwise. As a (former) chemist, 87 octane actually has more 'energy' per unit of fuel than 93 octane. There are more carbon-carbon bonds available to be broken and thus more energy to be had. This is lost in a high compression engine which will retard spark if knock is sensed, hence 'high octane' fuel delivers more power and performance - but only in a high compression or turbo motor (like the EB). But, for the majority of engines the majority of the time, it's just pouring money into Exxon-Mobil's pockets and giving their CEO an even bigger bonus. He makes a lot more money than I do, I'll keep the money for myself thank you.

So, if you're tracking the car, or have modified it, and are pushing the engine to the very limits of its capabilities, use 93 octane to reduce the risk of detonation. But, if you're driving on the street like a normal person, save the money for yourself instead of adding to the oil companies profits.

Right, higher octane is less power dense than lower octane. As I've said numerous times on this site (and others). You want the absolute least amount of octane you can get while still preventing detonation.

I'd really like to see someone have proof that the V8 retards timing while using 87 octane (with stock tune), which would imply you NEED more octane for better performance. Of course, I also agree that the performance loss isn't really that big of a deal either, in daily use at least.

But I still put in Premium in this car, it'll need it once I get a 91 octane tune anyhow, which won't be too far off.

 

[Spartan]

m.ford.com/cars/mustang/specifications/
Read detailed 2015 Ford Mustang exterior, interior, engine, specifications & more .


I hate to interject facts but it looks to me like Ford recommends premium for the GT.

Yes if you want to get max HP. The HP hit with 87 is nothing. You're basically throwing away money using 93 in the GT for a DD.

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