gasoline question

[Racer X]

Even if it isn't mandatory, stations and distributors can CHOOSE to sell E10. Cheap way to boost 87 octane gas to 89, and sell it for more money.

[wurm]

[quote Racer X]Even if it isn't mandatory, stations and distributors can CHOOSE to sell E10. Cheap way to boost 87 octane gas to 89, and sell it for more money.
So wait a minute. All this time I thought they were effectively diluting the gas with ethanol. You're saying it actually improves performance? Or am I inferring incorrectly?

(Yes, I admit I didn't read all the articles linked. Besides, I trust everyone here on the forum more than I do those professorial types and their biased opinions, anyway.)

[sscutchen]

[quote wurm][quote Racer X]Even if it isn't mandatory, stations and distributors can CHOOSE to sell E10. Cheap way to boost 87 octane gas to 89, and sell it for more money.
So wait a minute. All this time I thought they were effectively diluting the gas with ethanol. You're saying it actually improves performance? Or am I inferring incorrectly?
Ethanol has an octane blending value of 113.

Ethanol is hardly a cheap way to boost octane. It is much more expensive to deliver to your local station, and unless you live in the midwest where it is made, it is much more expensive to get to your local distribution hub.

A refiner does not take 87 octane gas and then simply add EtOH to it to get a higher octane. Gasoline blending is a complex science which must take into account much more than simply octane. Gasoline that is destined to be mixed with EtOH will be blended with a low vapor pressure and lower octane before it is shipped to the local distribution hub so that when it is mixed with EtOH in the delivery truck it will have the proper properties.

[BigGuynRusty]

In order for Ethanol to boost performance, your engine has to have a higher Compression Ratio, you can increase the timing, but that only helps a bit.
Ethanol has a higher octane number, but per pound carries less energy than gasoline.

BGnR