2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

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Darrell
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2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by Darrell »

Interesting article found via Insty:
The 2015 Ford Mustang with the 2.3-liter EcoBoost four-cylinder is a pretty potent package on paper. With 310 horsepower and 320 pound-feet of torque, it boasts better performance numbers than the 3.7-liter V6, but with better fuel economy as an added benefit.

However, if you're in the market for one of these boosted 'Stangs, you should probably keep in mind that it really prefers to gulp premium, 93-octane fuel. It can drink 87-octane swill in a pinch, but you're going to find significantly less power underfoot when pulling away. While it's not shocking that the ponies are dialed back with a lower grade of gasoline, an alleged page from a Ford training manual obtained by Mustang 6G purports to show just how much power is lost, though.

According to this document, the 2.3-liter EcoBoost makes 275 horsepower and 300 pound-feet of torque when running on lower octane fuel. That's a substantial reduction of about 11.3 percent compared to when the engine drinks 93 octane. Interestingly, according to Mustang 6G, that finding was a bit better than expected, because a Ford engineer reportedly said power would be down about 13 percent without altering peak torque.

In speaking with Autoblog, Paul Seredynski of Ford powertrain communications, objected to part of this document. While he couldn't confirm the specific losses listed for the Mustang EcoBoost, "torque remains unchanged" with lower octane gasoline, Seredynski said. He speculated this training manual page was "possibly from before the engine was certified" and therefore showed incorrect figures. Serendynski did confirm that the automaker recommends using 93 octane, and like all modern engines, the software adapts if it's lower. "Peak power would be reduced" by using a lesser grade, he confirmed.
http://www.autoblog.com/2015/01/05/2015 ... 87-octane/

How does this square with the oft-quoted statement that putting a higher octane fuel in the car doesn't help performance? Also, interesting that peak torque doesn't change. I wonder how my Mazda manages a 13-14 to one compression ratio on 87 octane. Heck, I noticed today that regular was going for $1.66 per gallon at my local station. I might pay for midgrade if the price would stay down. ;)
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Yogimus
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by Yogimus »

How does this square with the oft-quoted statement that putting a higher octane fuel in the car doesn't help performance?
It DOESN'T help in engines DESIGNED for low octane gas.
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PawPaw
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by PawPaw »

The Mustang needs, at a minimum, a 5.0 liter engine, or it's just a pale imitation of a Mustang.

A Mustang needs a V8. I'm surprised that Ford even offers a smaller engine.
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Yogimus
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by Yogimus »

The Ford Mustang is the new "Miata" marketed for college aged stupid people.
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PawPaw
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by PawPaw »

Yogimus wrote:The Ford Mustang is the new "Miata" marketed for college aged stupid people.
Well, there is that. I liked Mustangs, but I always chose cars for more practical concerns.

My car in college was a '69 Ford Fairlane, a totally practical family sedan. I bought it from a rich old lady on a private contract because the dealership was trying to screw her on the trade-in. I got it for $10.00 over the trade value.

Image
Picture for reference only.

That car had a 289 V8 and was loaded with all the options. It ran like a scalded ape, was comfortable, and the big back seat was long enough to stretch out on, with a partner. More than a few young ladies lost their virtue in that big back seat. Several were compromised on the front seat as well. Try doing that in a Mustang.

Gawd, I loved that car.
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BloodlessWeevil
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by BloodlessWeevil »

Darrell wrote: How does this square with the oft-quoted statement that putting a higher octane fuel in the car doesn't help performance?
Yogi got that one. Requiring higher octane allows engine designers to increase the compression ratio. Without a higher compression ratio there is no gain from an increased octane rating. A higher octane fuel has a higher autoignition pressure for a given temperature (or vice versa.)
I believe that the ecoboost engine is compensating for lower octane fuel by opening intake valves late and exhaust valves early to allow some of the intake air to flow straight out the exhaust, and thus reduce pressure. But that's just a wild guess.
Darrell wrote: Also, interesting that peak torque doesn't change. I wonder how my Mazda manages a 13-14 to one compression ratio on 87 octane.
Yeah... I'm not sure I believe Ford on that one. Anyhow, your Mazda is 13:1 if you are putting 87 octane gas in it. The 14:1 engine requires 91. The high compression ratios are made possible by reducing combustion temperature. Mazda has an interesting exhaust setup and they keep the revs down.
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randy
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by randy »

+1 on Yogi's comment (omigawd! what did I just say!?! :shock: )

I had a 1986 Dodge Daytona, 2.2L turbo charged. Based on rough estimates in a notebook I occasionally kept, it performed much better and got better mileage the higher the octane I fed it.

Unless I was using "gasahol" in hot weather, when it would give high revs with no power after about 2 hours on the road until I let it cool off. And then fed it real gasoline.
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slowpoke
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by slowpoke »

PawPaw wrote:The Mustang needs, at a minimum, a 5.0 liter engine, or it's just a pale imitation of a Mustang.

A Mustang needs a V8. I'm surprised that Ford even offers a smaller engine.
We are living in the second golden age of horsepower. its 1970 all over again. That 4 cyl mustang gets more horsepower and torque than the v8 did 10 years ago. Enjoy it, get something fast cause CAFE stardards are snaping the door shut on power just like they did before.
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g-man
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by g-man »

The turbo Mustang most likely dials back the timing and/or boost when knock is detected, which would happen when you feed it 87 octane fuel. Motors without knock sensors can't safely dial the HP up or down since they have no way to measure where 'too much fun' lives. And 'loses big power' is a semi-deceiving headline, since the damn thing still makes more ponies than any of the non-shelby fox-body Mustangs, to include the SVT Cobra R.

And since we've brushed up against the topic of college cars, I had a 1965 Ford Galaxie LTD with a 390 (running 428SCJ heads for a while) which would very nearly lift the left front under acceleration (suspension at full extension). User name is derived from that, vice being a .gov type... I've got a picture around somewhere, but it was not dissimilar from this one, including the color:
Image
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Greg
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Re: 2015 Ford Mustang EcoBoost Loses Big Power On 87 Octane

Post by Greg »

PawPaw wrote:The Mustang needs, at a minimum, a 5.0 liter engine, or it's just a pale imitation of a Mustang.

A Mustang needs a V8. I'm surprised that Ford even offers a smaller engine.
Ford knows what sells. Or at least, what *they* sell. You'd be surprised how many people buy V6 Mustangs.
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