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Regular or premium fuel 2.0 L ?

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I am confused, should I use reg. or premium. Dealer has to

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I'd go by the owner's manual.  For optimum performance though, user the higher octane rating :)

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I had wondered the same thing. Owner's manual says to use 87 octane for normal use, although it recommends a higher octane when a heavier load is placed on the engine, such as towing. Drove mine 550 miles the first couple of days after purchasing and used 87 octane. Seemed to run fine and still managed a respectable 28 mpg.

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It might make for an interesting "seat of the pants" comparison. Run a tank of each grade and see how much difference it makes, and also to see if a difference can be detected. It also will be interesting to see if fuel econ. is affected?

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Fuel economy can actually improve with 93 octane when the PCM can account for it. These EB engines love their octane ...

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Read this in the manual. The higher claimed fuel MPG was based on the use of 93 octane fuel. For an average of 30-45 cents per gallon more yowould have to have considerable MPG increase over 87. I don't have many miles on mine yet (700) but the first hwy trip yeilded 26 MPG's

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I think it's pretty cheesy that the 2015/2016 EB HP and TQ numbers are using 93 octane but the EPA mileage rating is using 87 octane. I mean nobody is buying the 2.0L for maximum performance, but it's misleading to use 93 octane in one case and 87 in another case and have them as published figures.

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I've been running 87 in mine since I purchased it. It had 411 miles on it when I bought it and now has 6,300 miles on it. I'm due for a fill up today and may try higher octane, just for kicks. I've been tracking my mileage after the first tank or two and have been averaging 21.4mpg. Granted my Edge is AWD and I bought it in September, so a lot of the mileage has been on winter blend fuel and snow tires.

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The math doesn't support using 93 octane...

 

Let's say you can get 26mpg on 87 octane and 10% more on 93 octane (that's generous - I seriously doubt there would be that much improvement).

15 gallons of 87 octane would get you 390 miles. 15 gallons of 93 octane would get you 429 miles.

But the 15 gallons of 87 would cost $25.49 and compared to $32.99 for the same 15 gallons of 93 octane (based on this morning's prices at the Shell closest to me: $1.699 for regular, $2.199 for premium).

That's 6.54 cents per mile on 87 octane and 7.69 cents per mile on 93 octane so it's cheaper to accept the lower mileage of the regular gas.

 

The numbers will be different depending on actual mileage and gas prices, but as long as the spread between regular and premium prices is greater than the percent improvement in mileage, the higher octane is a losing proposition (i.e. spending about 30% more to gain 10% mileage will never work regardless of actual gas prices). Even in the old days when there was only 10 cents separating each grade (20 cents from regular to premium), it wouldn't be worth it until the price of regular got over $2 per gallon.

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I know in my previous car, Cobalt SS SC, when I used regular it felt significantly slower and I lost about 15-20% mileage over using premium. And the car drove like crap for the next tank of premium as well. I actually had to do a ECM clear and have it relearn before I got all of the performance and mileage back. I have only run Premium in the new Sport 2.7EB we bought and mileage has been increasing every fill.

Edited by luminator

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Yes, that will happen with most cars. Most engine computers are programmed for a certain level of octane and will retard the ignition timing if lower octane is used (or for other reasons that cause engine knock such as stale fuel) to prevent damage from knock. That will cause a significant reduction in both performance and mileage. Your supercharged Cobalt required higher octane as its base fuel and when you used 87 octane it retarded the ignition timing to protect the engine. However, it will not advance the ignition timing if you use higher than specified octane so there is no performance gain from using something like Sunoco's 100 octane fuel. Basically it just passively does nothing until a knock sensor is triggered and then it reacts by retarding the timing.

 

The Edge computer (along with Mustang and several other Ford products, Chevy Camaro and Corvette LS V8s, Chrysler Hemi V8s, some Kia and Hyundai engines, etc.) is programmed somewhat differently. It is designed to run on regular (87) octane but it actively checks continually for knock and advances the ignition timing to just below the point where knocking starts allowing the engine to produce the most power and economy possible for the fuel currently in use. That means that using higher octane fuel will make a difference although that difference is not particularly dramatic. For example, a Mustang 5.0 Coyote engine produces 412 horsepower on 87 octane or 420 horsepower on 93 octane. That 2% increase is in peak horsepower at 6,500 rpm so although it can make a difference in 1/4 mile times, it is not something you would ever notice in daily driving.

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I put 91 in at my last fill up. I couldn't believe the price difference between 87 and 91. I'll be filling up again today but will go back to 87. I don't know if it was just butt dyno or what, but the engine seemed a bit more lively on the 91.

 

There was one improvement that I know for a fact, however. On 87 every day when approaching the highway on ramp at around 45-50mph, there's a noticeable RPM surge with the motor under load. It'll rev a little higher, drop back down, and then rev up again. You can watch the needle move. On 91 that occurrence seems to have disappeared.

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What you're describing could not be attributed to increased octane. Higher octane fuel is not "better" fuel (despite the oil companies calling it "premium") - it's just more resistant to detonation and engine knock. However, there is one factor that could explain the difference... many stations (especially in the north) sell "premium" fuel that is not only higher octane but also contains less ethanol. This can be the case even if the pump has a sign that says the fuel "may contain up to 10% ethanol" (the key words being "up to"). Ethanol has about 33% less energy content than gasoline so pure gasoline will always give a performance boost over E10 or E15 blends. That boost is usually enough to be felt by the "butt dyno" and will also contribute to better mileage and a smoother idle. Whether it's worth the higher cost is a personal choice... especially if you can't be sure whether it's a blend or not.

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Could be. I just filled up and saw a 1.10mpg increase from my last fill up but the mileage on this tank was still average. That was the furthest I've gone on a tank of gas since December but still nothing earth shattering. Oh well. Figured it was worth a shot. I don't think I've ever put anything more than 87 in a car before so I figured it was worth a shot to see what would happen in this case.

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The surge on regular fuel compared to premium could also be explained that on regular the PCM detected engine knock and thus retarded the ignition (I think that's the term) which lead to increased rpm to compensate for reduced engine power. While with premium, engine knocking wasn't present & hence no change in power & rpm.

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Maybe I'm just old skool, but with a boosted motor, I'd rather err on the side of higher octane. Ignition knock, even just a tiny bit, can cause significant damage to pistons... and the damage can be cumulative. Yes, 87 octane is less expensive, and computers are controlling spark advance, retarding it when the sensors detect pre-ignition, but blowing a hole through the top of a piston, will end up costing a whole lot more, than the buck or two saved on each fill-up.

Plus, there's the advantage of increased performance a boosted motor brings to the plate. I've always gone by what the owners manual stated as far as octane, but when an option is provided, I use the higher octane.

For me, at least, the added cost is negligible vs. the peace of mind.

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There is absolutely no danger of engine damage with 87 octane. Remember these engines were designed with boost from the get go. You're not adding a turbo to a NA engine that wasn't designed for it. They've accounted for all of that with the compression ratio and spark advance settings.

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The assumption here is that Top Tier fuel is being used when pumping 87 octane. The engine may not spontaneously combust, but it can be an unsettling experience when it decides to shut down for self preservation.

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Back when premium was only 20-30 cents higher than regular, I would have entered this thread telling everyone to suck it up and quit being cheap. If you own a Sport, I still may do that as it is a performance vehicle. The cost of premium these days is unreal. Around town, I see premium between 60 to 100 cents higher with the average premium being about 80 cents. I am heading to Costco now because premium there is only 10 cents higher than what regular is selling for at the Shell or BP next to me.

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The thing is... even if the sport was a performance vehicle (it's not, it's a trim level of a CUV with at best a V6), the difference in performance from higher octane fuel is minimal and not even noticeable in normal driving. Even the Mustang GT with Coyote V8 only goes from 412 HP on 87 octane to 420 HP on 93 octane. That's a 2% gain in peak horsepower at 6500 RPM - an engine speed most people never see except on the track. That small gain will show up in time slips but you would never notice it on the street. It's certainly not worth the extra fuel cost for anything other than racing.

 

Now, if you want a "seat-of-the-pants" boost in power and throttle response, find some non-ethanol fuel. Often called marine gas because it is used in boats and sold at most marinas, it commonly comes in 89 octane mid-grade and is standard for many northern suppliers premium (91 or 93 octane) - especially in Canada. Pure gas has 32% more energy than ethanol so using it improves both mileage and performance. Unfortunately, it is usually just as expensive as E10 premium but at least you'll be able to feel the difference for your money.

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Actually premium can make a huge difference on the street. There may not be as big of a change in peak power, but it is how the power is delivered that makes the difference. One thing you notice on GTDI engines is how the torque curve flattens with bigger low and midrange gains. You cannot compare a n/a engine to a forced induction engine either. Considering the Sport hits 0-60 in 5.6 seconds with the 1/4 mile in 14.2, I say that qualifies as a performance vehicle. This is also by far the best handling SUV I have ever seen. The Sport was so impressive that I passed on the WRX STI(too punishing) and the Fusion Sport.

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The 16 Fusion Sport, junehhan?

 

OK I see there wasn't one. So you liked the Edge even more than the 2017 Fusion Sport?

Edited by WWWPerfA_ZN0W

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The 16 Fusion Sport, junehhan?

OK I see there wasn't one. So you liked the Edge even more than the 2017 Fusion Sport?

Yes but it was extremely close. They got 5 Fusion Sports in and they sold instantly except for one which I was looking at. My dealer let me take the Edge for an extended test drive and that ultimately sealed the deal. The Edge got dinged because this active steering system is unholy and unnatural, but got a huge plus because it honestly felt just as fast and torquey as the Fusion Sport while maintaining a huge increase in utility. Granted I never went above half throttle, but they felt very similar in how they drive as you could tell that they shared the same CD4 platform.

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