MPG-Straight Gas vs E10

[Jim Allen]

If you do some research (including the study linked above), you will find that, unless the vehicle is tuned for an ethanol blend (basically a flex fuel vehicle), a mileage gain is improbable at best. More than likely, any gains noted will be from other things, not the blended fuel. It's a pretty universal thing... just not as much energy in the fuel and the tuning needs of the engine change with the amount of ethanol which may throw it off more. Some of the cars in the study went excessively lean at WOT, a situation which could be damaging to the engine (of course ecomodder never open the throttle ( : < ). When the vehicle is properly tuned, it can do as well on blended as with straight gas, or nearly so. I'm going to be doing a custom tune on my F-150 in the near future and with blended fuels so prevalent, I may factor an E10 blend into it and see where it takes me.

[DoctorP82]

Originally Posted by KJSatz

E10 is mandated throughout Missouri.

Are you sure? MFA Oil is who supplies Breaktime, and its their super that contains E10, but regular is not advertised as an E10 blend. They do advertise the E10 super as having an 89 octane whereas regular is 87, though with the general consensus that ethanol decreases fuel economy I think the octane rating is moot.

On another note, how is using ethanol additive better just because it's renewable? Because of government requirements for farmers to put a certain percentage of corn crop towards ethanol fuel production we have an increase in that food crop cost (FOOD, which I would take over oil). Also, with the decrease in fuel efficiency with ethanol additives, wouldn't you find that there is more of a demand for oil? Nevermind that you are diluting it.

I would be interested in whether the ethanol-diluted gas goes further on the same price and how that compensates for the decrease efficiency. However, not everyone is as fuel consciencious with the way they drive as ecomodders are, so I'm not sure about it breaking even with people who still guzzle gas.

[Jim Allen]

DoctorP82: Well said overall. Ethanol does increase the octane rating of the fuel, so you see it in some premium of midgrade fuels.

I ran a quick-n-dirty scenario (20 mpg) and found that with a 4 percent drop in FE from E10, the blended fuel would have to be $0.09 cheaper per gallon to break even. I'm not seeing any discounts here, so all I got is the drop in MPG. Wooo-hoo! Or should I say, Boo-Hoo!