Does premium gas make a big difference over regular?

[w3rkn]

I believe my 2016 stock ecoboost should achieve around 145mph but I only get to about 128mph on regular gas.

I read somewhere that the cars top end 310hp can only be achieved with premium gas, will with regular it only gets to about 270hp, is this true?

Or do I have something else weird going on with my engine, which up to this point, 32,000 miles, hasn't had any problems.

Terry

Answer: Yes.

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[tcman54]

Been driving around on my first tank full of 93 octane compared to 87 that I usually use and the car somehow seems worse.

Do I have to run a few tank fulls for the car to get use to the 93?

TC

 

[ChaoticFury09]

Been driving around on my first tank full of 93 octane compared to 87 that I usually use and the car somehow seems worse.

Do I have to run a few tank fulls for the car to get use to the 93?

TC

Yes. It will relearn the octane. I would give it three tanks.

 

[AlmostFamous]

As for horsepower on the 5.0, the 2015-2017 GT was down around 10HP on 87 vs 93 during. For anyone doing a SOTP test, 10hp really is negligible. My guess is the 2018+ 5.0 having both port an direct injection is going to be similar

10 peak horsepower. I agree, that’s neglible but the dropoff in power was much more severe in the mid-range.

 

[Furious18]

That is not the recommended octane, just the octane the used to achieve max horsepower. Minimum octane requirements remain at 87.

As for horsepower on the 5.0, the 2015-2017 GT was down around 10HP on 87 vs 93 during. For anyone doing a SOTP test, 10hp really is negligible. My guess is the 2018+ 5.0 having both port an direct injection is going to be similar.

The full report can be seen here:
file:///C:/Users/204056460/Downloads/Premium-Fuel-Phase-II-Research-Report-FINAL.pdf

Probably worse on 18s. They are already very octane limited stock. The higher compression needs more octane

 

[Ebm]

Probably worse on 18s. They are already very octane limited stock. The higher compression needs more octane

So do you think Ford made the new(18+) Mustang run on 87 octane to net more sales?

The LT1(Camaro SS) runs like doo-doo on 87 octane. That car needs premium to run right. Maybe because it's strictly GDI and not PFI and GDI like the new Mustang.

 

[Deleted member 35644]

All automakers have a subset of consumers that just buy a car because they like the way it looks, or because it's a two-door, or whatever reason that has nothing to do with performance. These people are just putting gas in it and driving it, without a single thought of maximum horsepower, detonation, or the condition of their combustion chambers from one day to the next. Their primary focus is "it's shiny" and "I got a good deal on it", and these folks have no interest in paying for premium fuel. This is the subset they market 87-compatible cars to, and it's a very large subset. They're not worried that these people will notice a 10hp drop in power, because....they won't. Would Mustang sales suffer if the car required 91 or 93? Absolutely.

 

[Furious18]

So do you think Ford made the new(18+) Mustang run on 87 octane to net more sales?

The LT1(Camaro SS) runs like doo-doo on 87 octane. That car needs premium to run right. Maybe because it's strictly GDI and not PFI and GDI like the new Mustang.

It has a advanced ecu and they know that some people will run 87. If bet that timing would be retarded a lot on 87 and make a lot less then 91.

 

[lacanteen]

All automakers have a subset of consumers that just buy a car because they like the way it looks, or because it's a two-door, or whatever reason that has nothing to do with performance. These people are just putting gas in it and driving it, without a single thought of maximum horsepower, detonation, or the condition of their combustion chambers from one day to the next. Their primary focus is "it's shiny" and "I got a good deal on it", and these folks have no interest in paying for premium fuel. This is the subset they market 87-compatible cars to, and it's a very large subset. They're not worried that these people will notice a 10hp drop in power, because....they won't. Would Mustang sales suffer if the car required 91 or 93? Absolutely.

I agree, well said. I almost passed on a great deal in the late 90's on a Mercedes because it required premium gasoline. That car was a land barge around town but on the interstate it was a magic carpet ride. WOT? Hang on!

 

[millhouse]

10 peak horsepower. I agree, that’s neglible but the dropoff in power was much more severe in the mid-range.

Actually, it's quite small in the midrange.

Per the report:
"At the low end and higher end of the speeds tested, the horsepower and torque numbers were essentially the same for both fuels. However, the premium gasoline produced a marginal increase in the midrange."

 

[NoVaGT]

All automakers have a subset of consumers that just buy a car because they like the way it looks, or because it's a two-door, or whatever reason that has nothing to do with performance. These people are just putting gas in it and driving it, without a single thought of maximum horsepower, detonation, or the condition of their combustion chambers from one day to the next. Their primary focus is "it's shiny" and "I got a good deal on it", and these folks have no interest in paying for premium fuel. This is the subset they market 87-compatible cars to, and it's a very large subset. They're not worried that these people will notice a 10hp drop in power, because....they won't. Would Mustang sales suffer if the car required 91 or 93? Absolutely.

Probably 70% of Mustang owners don't give a crap about performance, and don't even know what an octane rating is. They aren't a "subset", they are the vast majority that buy the car.

There's no "marketing" behind making cars "87-compatible", it's just simple technology that all cars have. All most owners care about is "what is the cheapest gas I can find near me?" It's just a simple necessity of mass-produced people-movers.

Hell, I can't think of any non-exotic vehicle that doesn't run on 87 octane.

 

[Grintch]

Why bother with regular? It’s a performance car and the yearly cost isn’t that much more between the two. I want max performance when I want it.

The cost of regular vs premium is like a 30% difference in my area. That is about the difference between the fuel economy of my Mustang GT verses my Focus ST.

It will not hurt your car, and while it will reduce the performance slightly, it is not enough to matter on the street. It apparently does make more difference on the EB than the V8.

Save it for the track when your are using the car to it's limits, and every horsepower counts.

 

[Zinc03svt]

If the stang is your daily driver for commuting purposes by all means buy the lower octane/cheaper gas. Especially if you do a lot of hwy stuff.

But some of us buy these things mainly as play toys/weekend cars/track fun etc. We want the maximum performance aka “max timing” all the time. Not to jump off topic from 87-93 pump, but the difference in a 18 GT with 87 octane and one that has a good E85 tune is night and day even in part throttle driving. That difference is way more than 5-10hp btw. Throttle response (under the curve) and pick up/torque from a stop is very strong as though the motor is barely working at all. I will step off my E85 band wagon now... ;).

 

[AlmostFamous]

Actually, it's quite small in the midrange.

Per the report:
"At the low end and higher end of the speeds tested, the horsepower and torque numbers were essentially the same for both fuels. However, the premium gasoline produced a marginal increase in the midrange."

Disclaimer, Gen 1 Coyote. Below is a dyno graph showing the difference between 87 octane and 93 octane. According to the shop, no other changes were made to the car/tune/etc. Similar weather for both passes, carat normal operating temperatures.

Note: 6 RWHP peak difference. Not that much, but look at the difference in the mid range, especially 4500-6000 rpm. Looks to be ~20 RWHP difference in places (corresponding increase in torque, of course).

 

[millhouse]

Probably worse on 18s. They are already very octane limited stock. The higher compression needs more octane

Maybe, Maybe not.

Something to keep in mind, most

you do a lot of hwy stuff.

But some of us buy these things mainly

Disclaimer, Gen 1 Coyote. Below is a dyno graph showing the difference between 87 octane and 93 octane. According to the shop, no other changes were made to the car/tune/etc. Similar weather for both passes, carat normal operating temperatures.

Note: 6 RWHP peak difference. Not that much, but look at the difference in the mid range, especially 4500-6000 rpm. Looks to be ~20 RWHP difference in places (corresponding increase in torque, of course).

I've seen that dyno before, but I'm sorry...the AAA report is much more accurate as it uses scientific method along with standardized testing procedure (same room temp, same engine temp, same warmup duration etc.).

Per the report,

"All runs were averaged using a Bessel Spline interpolation with no extrapolation of data. The averaged data was then graphed and integrated to provide the numerical comparisons for dynamic torque and horsepower produced using premium compared to regular gasoline."

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