Worse m.p.g. Using higher octane

[Josebd]

Is it possible? I usually use 86 octane,friday I was down to half a tank and filled up with 88 octane (philips 66),I can usually go 100 miles before it gets to 3/4 of a tank,right now I’m at 78 miles already at 3/4 of a tank

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[12Bravo20]

Could the 88 Octane have more ethanol in it?

And it usually take 2-3 tanks full to see a change with different octane rules are used. And since you only put half a tank in, it is possible that you got some bad fuel.

 

[Muscleford]

There can be lot of variation as to how full you get the tank and the corresponding MPG will vary. I would not put much accuracy into MPG on on tank.

 

[AzScorpion]

Is it possible? I usually use 86 octane,friday I was down to half a tank and filled up with 88 octane (philips 66),I can usually go 100 miles before it gets to 3/4 of a tank,right now I’m at 78 miles already at 3/4 of a tank

I ran 87 for the first year then I switched to 91. When I did that I noticed a slight increase of about 1 mpg. IIRC the owners manual recommends a minimum of 87 so I would try and stick with that or higher.

 

[daniel3507]

I would give it a couple tanks and make sure you calculate by hand and don't just rely on the computer. I'm in the process of adjusting the computer mpg calculator to be more accurate.

 

[D Fresh]

The decision on octane is not one to base off of MPG IMHO.

The reasons for using higher octane are for better performance and engine durability.

The knock sensor will advance timing when less or no knock is present. I.E. using premium fuel.

I've been driving small displacement turbo vehicles for over 15 years. They always get premium. In fact they always REQUIRE premium. Except for the ecoboost whose knock sensor will retard timing for lesser fuels.

If you want to put cheap gas in it you should've bought something with an NA engine.

 

[Frenchy]

Is it possible? I usually use 86 octane,friday I was down to half a tank and filled up with 88 octane (philips 66),I can usually go 100 miles before it gets to 3/4 of a tank,right now I’m at 78 miles already at 3/4 of a tank

You're not being smart by using 86 octane to begin with. Ford States minimum octane rating for the truck is 87 for a reason. It also States for better performance and for towing to use 91 and higher. If you are getting lower fuel mileage with higher octane chances are your foot is in the pedal way too much

 

[Radioman]

Is it possible? I usually use 86 octane,friday I was down to half a tank and filled up with 88 octane (philips 66),I can usually go 100 miles before it gets to 3/4 of a tank,right now I’m at 78 miles already at 3/4 of a tank

I would not expect to get accurate mileage reading until you have driven a least 2 or 3 tankfuls. Also you should purchase gasoline with higher octane.

 

[LoneRNGR]

Is it possible?

Octane does not really determine MPG. The different octane ratings should contain similar amounts of energy.

There can be exceptions, like if you are getting knock with lower octane fuel, then using higher octane might improve mpg, but then you would have a different problem.

We have learned that the Ranger (and Bronco and Explorer) adjusts its tuning based on the octane with higher octane producing more horsepower and torque.

I would imagine that if you continue using higher octane, especially from various sources, you will see that mpg will remain about the same.

 

[VegasRanger]

Couldn’t tell ya, I’ve been running 91 since day one, especially since it’s been 105+ degrees since the day I bought it and the manual recommends 91 during hot weather.

 

[kieefer]

You may be on to something.
I was running premium since new and now that gas is hitting $3.00 in my area I’ve been running regular for the past three months.
I was consistently getting 19-20 with premium but now I have been getting 22mpg.

 

[dapakattack]

You may be on to something.
I was running premium since new and now that gas is hitting $3.00 in my area I’ve been running regular for the past three months.
I was consistently getting 19-20 with premium but now I have been getting 22mpg.

Could be because of warmer weather:
https://www.greencarreports.com/news/1078126_getting-better-gas-mileage-in-warm-weather-heres-why

 

[AzScorpion]

Could be because of warmer weather:
https://www.greencarreports.com/news/1078126_getting-better-gas-mileage-in-warm-weather-heres-why

Winter will do it too. We don't get much of a winter here but I'll still lose a mile or two letting it warm up more in the mornings.

 

[Motorpsychology]

You may be on to something.
I was running premium since new and now that gas is hitting $3.00 in my area I’ve been running regular for the past three months.
I was consistently getting 19-20 with premium but now I have been getting 22mpg.

I think it depends on how the 91 octane is formulated. If they do it partially or totally with additional ethanol, milage could be worse than that using E-0 non-oxy premium. I only ran two tanks of 91 oct E-0, and that was when the truck had less than a thousand miles, and we were in the Black Hills. Later drove home against the wind at 80mph, so I don't have a fair comparison with 87oct E-10.
I have never reset the Fuel economy page in the Driver Information Display since news after 5167 miles I've averaged 24.4 mpg and 49 mph all but those two tanks mentioned earlier on 87oct E10

 

[GitRDone]

In Florida our regular octane is 87. I have occasionally seen 88 offered alongside it (and wondered why). Someone told me the 88 contains more ethanol than the 87, which could explain lower efficiency/mpg despite the higher octane.

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