MPG using different grades of fuel

[STARCOMMTREY1]

My Maverick is scheduled to be built in the next few days, and I have done some research, and found in the manual that Ford recommends 91 octane, but 87 octane is required. To those Hybrid XL owners (with the steel rims), what is your MPG numbers, and what grade of fuel do you use? I am trying to see if there is an MPG increase, and if that MPG increase is large enough to offset the higher cost of premium for a lower total cost per mile for gas. Thanks in advance!!

Hybrid os 87 recommended. 91 is for EB. .

Sponsored

 

[Espeer]

You will get exactly 0% mpg increase by using higher octane fuel in your maverick. Octane in simple terms is the fuels resistance to detonation. 87 octane has the same energy density per gallon as 91 octane.

You will however get better fuel economy if you found ethanol free gasoline, as E10 gasoline that contains up to 10% ethanol has less energy per gallon than ethanol free. But it's also expensive

A bit over simplified, in my opinion. What do you think the ecu does if it detects detonation? It can retard ignition timing. That can absolutely have a detrimental effect on mpg.

 

[Mavman123]

A bit over simplified, in my opinion. What do you think the ecu does if it detects detonation? It can retard ignition timing. That can absolutely have a detrimental effect on mpg.

Absolutely agree, which is why the manual recommends higher octane fuel only when towing. This is where you may get the engine hotter than normal everyday driving and therefore the knock sensor/ecu will have to adjust timing to accommodate.

Normal driving will see no mpg difference between regular and premium fuel. However, ethanol free fuel will get you 3-4% efficiency gains. But it costs much more than 3 to 4% over E10 lol

 

[Mavman123]

Hybrid os 87 recommended. 91 is for EB. .

Premium is recommended for towing. 87 is fine for everyday driving Ecoboost or hybrid.

Also just for context, I normally put 87 octane 10% ethanol into my Ecoboost and I'm 2500 miles in averaging anywhere from 28 to 30mpg depending on my driving habits and traffic. I'd say I drive much more "highway" than most (lots of 40 to 60mph drives). I also purposely drive to achieve maximum fuel efficiency so I would expect someone that doesn't drive for efficiency would see around 24 to 25mpg

 

[MauRoba]

“The performance gained by using premium fuel is most noticeable in hot weather…..”

OP states they’re from Austin () so they know good BBQ and hot weather.

 

[rlhdweman]

Absolutely agree, which is why the manual recommends higher octane fuel only when towing. This is where you may get the engine hotter than normal everyday driving and therefore the knock sensor/ecu will have to adjust timing to accommodate.

Normal driving will see no mpg difference between regular and premium fuel. However, ethanol free fuel will get you 3-4% efficiency gains. But it costs much more than 3 to 4% over E10 lol

My Maverick gets 10% better fuel economy without ethanol. All of my vehicles from the early 90's to now got between 10-15% better mileage without ethanol. There were no exceptions.

 

[Flomounier1]

MPG will really vary depending on whether your commute is %80 freeway, 50/50, or %80 city streets.

Using regular 87 octane in my Maverick doing about %60 city %40 freeway driving, I got 39mpg roughly.

91 Octane is only recommended when driving in really hot weather according to the manual.

 

[MTMaverick]

Oops, didn't read the manual, have been using 85 octane gas.

 

[bgn]

Oops, didn't read the manual, have been using 85 octane gas.

Now you know and fairly early, too!

 

[Eagle11]

yes ethanol free.... all gas in the US has been lead free for a long time. And also I agree with you about the hybrid without the turbo there is no point in running more than 87

NOt all Fuels have, if you head down to your local airport, they have Low Lead fuel for the prop planes.

 

[Eagle11]

I think you mean ethanol free, not led free. I get a solid 3 mpg better using 91 no ethanol vs 87 E-10 with my EB. I am currently getting a little over 31 COMBINED mpg. I don't think the difference will be as large on the hybrid as the ICE isn't always running like the EB. It still cost me a little more, I'm getting 10% better mpg, but @ 16% higher cost. I'll pay it, I don't support the use of ethanol in fuel, that's a whole other long discussion not really for this website.

Well see, on my next fill up I'll use 91 in Hybrid, I'm averaging just under 47 MPG with my Hybrid.

 

[bdaniel230]

My Maverick is scheduled to be built in the next few days, and I have done some research, and found in the manual that Ford recommends 91 octane, but 87 octane is required. To those Hybrid XL owners (with the steel rims), what is your MPG numbers, and what grade of fuel do you use? I am trying to see if there is an MPG increase, and if that MPG increase is large enough to offset the higher cost of premium for a lower total cost per mile for gas. Thanks in advance!!

I have looked at this with my EB XLT and I found that the offset was a wash. I got 2 to 3 mpg better on 91 octane E0 than on 87 octane E0 which makes about a gallon and a half difference which is now ~$7 a tankful. The difference in cost is about the same at the 91 octane is $0.45 per gallon more expensive than 87.
I just got back from a trip from Southwest Idaho to Milwaukee, Wisconsin (~3700 miles) and my average mpg was 26.5, with the highest being on 91 octane non-ethanol at 27.5 mpg and the lowest with 91 0ctane E10 at 23.6 mpg. Difficult to blame the E10 for all of that as it was the section of the trip from Lincoln, Ne to Cheyenne, Wy. But I think that 60% of the difference was from the E10.

In all, as I say, in my truck it has been a wash, but remember using lower octane levels causes more soot to build up in the turbo. I noted that when I had to punch it to pass or get around an accident waiting to happen, I would see a good puff of grey smoke from the exhaust. And I was averaging about 5 mph faster than the speed limit all the way, slowest was in Wyoming during the snow storm in a construction zone and that was a grateful 45 mph.

 

[MavDave]

NOt all Fuels have, if you head down to your local airport, they have Low Lead fuel for the prop planes.

This is true, but I ain't trying to pay for aviation grade fule for my Maverick.

 

[Eagle11]

This is true, but I ain't trying to pay for aviation grade fule for my Maverick.

That is how I feel about using higher octane fuel in the maverick, the added 2 or 3 MPG v cost doesn't add up. Now, in my M5 I'll add 102 octane when I want to have fun, it's not for the MPG, it's about the HP gain.

 

[MavDave]

I am willing to pay the little extra for at least mid-grade. But I am also in Houston so we are 90+ from April to October. Even if it isn't necessary I am willing to pay for the higher grade to insure the longevity of my internals. They say 87 is fine but I have yet to see a turbo engine with 200k that ran 87 all the time. But then again I don't see everything so maybe they are out there

Sponsored