Should I switch to premium fuel?

[DMEARC]

I'm about 1100 miles into my Outer Banks and I've noticed that the MPG hasn't been what I expected at about a combined 21 or 22 MPG. I've had a healthy mix of both city and highway driving. On the highway alone, I get about 24-25 MPG. In the city, I get closer to 19 or 20. It's gotten as low as 16 or 17. I'm hoping there's not a mechanical issue, but I do know that Ford recommends using fuel with higher octane.

I did some calculations— based on a combined 22 MPG on regular fuel, gas prices in my area, and my yearly mileage, I would need to get at least 24.5 MPG combined in order to "break even" and make buying premium fuel financially worth it. Anything lower than that would provide marginal MPG that is too low to justify the extra cost. If anyone wants my spreadsheet on how I calculated this feel free to let me know.

For those who use premium fuel, have you noticed an improvement in MPG compared to regular? Thanks!

Edit: forgot to add that I try to use Eco mode as much as possible and have auto-start/stop turned on.

The easiest way to gain more MPG is to accelerate slower, and drive slower. Do not carry any extra weight that you do not need. Do not carry extra “stuff” on the outside of the vehicle (any addition to the outside of the vehicle will add drag).
I do a lot of highway driving and frequently average mid 30’s MPG in my OB using 87 octane. City driving is usually high 20’s MPG. I also run higher tire pressures and use ECO on the highway.

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[DMEARC]

You mentioned that you drive in Eco mode on a regular basis. I also have a ‘22 Outer Banks with 1900 miles where I am now averaging over 25 mpg. I played around with normal, eco, and sport and for me, the normal did better by at least 2 mpg over eco and sport. It may just be my driving style, but I’d suggest doing a tank or two on Normal only mode and see if that helps.

If you do, I’d be curious what your results are.

ECO‘s biggest advantage is cylinder deactivation, which IIRC will only happen under certain circumstances like driving at a steady speed for so many minutes (I.e. highway driving). The reduction in gas pedal sensitivity and the transmission gear shift map change helps, but it doesn’t really shine until you put some highway miles on it.

 

[DMEARC]

The side that thinks premium is cost effective reminds me of the blind crowd that thinks if it cost more it’s better.

If and ONLY IF your car is tuned to take advantage of a higher anti knock formula you can pull loads up hills better at higher rpm’s ONLY.

Some modern cars DO get better fuel economy with premium. The problem with your statement is that you are thinking of older cars. Most modern cars are tuned to take advantage of higher octane in an effort to squeeze as much performance out of them as possible.
Some modern cars will experience less MPG on lower octane simply because the timing is retarded to prevent knocking.

 

[MMR_A51OBX]

I don't get all these numbers in the 20s. I've had probably a half dozen or more fill ups since purchasing and I am still hovering at 30-32 mpg. I have an Outer Banks and do mostly highway (that might be why). I work early mornings, so my drive is almost all green lights and I drive like a Grandma, or someone who hates dealing with the Fuzz (hall monitors with guns). I basically don't go over 65, and that's fast for me considering my highway of choice maxes at 55 (not that anyone bothers to pay attention to that, some drive in excess of 80 - ballsy or moronic?).

Oh, and it's pretty much set to Eco Mode all the time, unless I need to make a quick pullout into busy traffic, then Sport Mode gets me up to speed like the East Australian Current to a baby sea turtle.

Either way, I don't have any add-ons, so I guess YMMV (literally).

 

[Mark S.]

Some modern cars will experience less MPG on lower octane simply because the timing is retarded to prevent knocking.

I’ve looked far and wide for data to back this claim without success. Do happen to have a link to any evidence? For engines that can burn regular or premium timing is retarded to reduce power demand, which concurrently reduces heat. Generally speaking, less power means less fuel burned.

 

[DMEARC]

I’ve looked far and wide for data to back this claim without success. Do happen to have a link to any evidence? For engines that can burn regular or premium timing is retarded to reduce power demand, which concurrently reduces heat. Generally speaking, less power means less fuel burned.

I’ll see what I’ve got.

In the meantime, just because you are burning less fuel and making less power does not necessarily mean you are gaining MPG if the fuel is not being burned efficiently. This is why retarding the timing can hurt MPG.

 

[DMEARC]

I don't get all these numbers in the 20s. I've had probably a half dozen or more fill ups since purchasing and I am still hovering at 30-32 mpg. I have an Outer Banks and do mostly highway (that might be why). I work early mornings, so my drive is almost all green lights and I drive like a Grandma, or someone who hates dealing with the Fuzz (hall monitors with guns). I basically don't go over 65, and that's fast for me considering my highway of choice maxes at 55 (not that anyone bothers to pay attention to that, some drive in excess of 80 - ballsy or moronic?).

Oh, and it's pretty much set to Eco Mode all the time, unless I need to make a quick pullout into busy traffic, then Sport Mode gets me up to speed like the East Australian Current to a baby sea turtle.

Either way, I don't have any add-ons, so I guess YMMV (literally).

It‘s easy to exceed the Monroney label estimated MPG. It’s also very easy to do much worse.
You see the people in the latter category everyday: racing from stop light to stop light, racing down the highway, engine idling away at long red lights or while eating lunch in their car with the AC on, etc. It takes a determined mindset to do better with fuel usage. Some people would rather not put forth the effort.

 

[JAD67428]

Designed for performance cars with large, powerful engines, premium also helps minimize the risk of preignition inside highly-stressed, hot engine cylinders.

On a track, the extra boost given by premium can mean a few tenths of a second difference on a lap time.

In the real world, it barely affects performance, or fuel economy.

Consumer Reports advises that premium should only really be used in your car if your owner’s manual mandates it. In our experience, only a handful of everyday cars are tuned to run better on premium.

 

[JAD67428]

I'm about 1100 miles into my Outer Banks and I've noticed that the MPG hasn't been what I expected at about a combined 21 or 22 MPG. I've had a healthy mix of both city and highway driving. On the highway alone, I get about 24-25 MPG. In the city, I get closer to 19 or 20. It's gotten as low as 16 or 17. I'm hoping there's not a mechanical issue, but I do know that Ford recommends using fuel with higher octane.

I did some calculations— based on a combined 22 MPG on regular fuel, gas prices in my area, and my yearly mileage, I would need to get at least 24.5 MPG combined in order to "break even" and make buying premium fuel financially worth it. Anything lower than that would provide marginal MPG that is too low to justify the extra cost. If anyone wants my spreadsheet on how I calculated this feel free to let me know.

For those who use premium fuel, have you noticed an improvement in MPG compared to regular? Thanks!

Edit: forgot to add that I try to use Eco mode as much as possible and have auto-start/stop turned on.

I would have to ask you a question first, do you plan to keep the vehicle for say 150.000 thousand miles ? If you say yes to that question I would “recommend “ that you use premium. That’s what I’m going to try to do is keep mine for at least 10 years so I’m using premium, but I think it’s a more of a personal “choice” to use. I believe in that old adage “you get what you pay for” so I want my little 3 cylinder to get to 150.000 thousand or there about.

 

[GulfCoastBronco]

First 1,000 miles I was around 22 mpg as well. I tried to not give it much thought and hoped it would even out. I’m around 7,500 and getting closer to 26 mpg now. I’ve only reset my mpg calculation 1 time and it shows 25.5 mpg for life of engine so far. I believe it will level off.

 

[Mark S.]

I’ll see what I’ve got.

In the meantime, just because you are burning less fuel and making less power does not necessarily mean you are gaining MPG if the fuel is not being burned efficiently. This is why retarding the timing can hurt MPG.

I didn’t say you’re gaining MPG, just that you’re producing less power which is generally associated with burning less fuel. When burning premium, timing is advanced only at high power demand—that’s one of the control parameters changed to get the 5-10% power I gain from using premium. But there is no improvement in efficiency, you just get more power—and that power requires more fuel.

 

[13MikeH]

Lol...if you have the cash/vault these days, pay the $17 a gallon for premium. And squeeze out the extra ten bucks a month in savings. If you don't...pay the $15 a gallon for 87 and go about your day. How you drive will make a bigger impact than the octane rating all day every day.
I stay at or just over the limit in town 35-45 most roads. I run 73-79 with cruise on the expressway. I pull 24-30 mpg with the 2.0 badlands.

 

[bjbena]

You mentioned that you drive in Eco mode on a regular basis. I also have a ‘22 Outer Banks with 1900 miles where I am now averaging over 25 mpg. I played around with normal, eco, and sport and for me, the normal did better by at least 2 mpg over eco and sport. It may just be my driving style, but I’d suggest doing a tank or two on Normal only mode and see if that helps.

If you do, I’d be curious what your results are.

When I had my 21 OB I was averaging 32mpg in ECO. It was so good I never bothered driving in Normal.

 

[Mark S.]

What about chemistry..? Is there corn alcohol in "low octane" (and not in "high octane").
If so, does that mean anything?

Almost all gasoline sold in the U.S. contains 10% ethanol. Ethanol actually is higher octane than straight gasoline, which is why it’s used as a racing fuel.

Heading home in a strong headwind at 80mph I did feel something vibrating under my floorboard. It went away at slower speeds.

That sounds like something wind related.

 

[13MikeH]

Almost all gasoline sold in the U.S. contains 10% ethanol. Ethanol actually is higher octane than straight gasoline, which is why it’s used as a racing fuel.


That sounds like something wind related.

Actually not really. It's used in racing fuel (assuming you are referring to NASCAR). I worked several years with fire and safety quite often at the fuel island. Chicago and Michigan actually used a tanker. The move to E-85 was a publicity move. They still burn about four gallons per mile...trust me when I say...the ethanol isn't impacting their 700-900hp motors. I spoke with a lot of engineers and engine tuners to pass my day...it's crazy the tricks of the trade. .

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