Actualy, there is something on the market for Small engines ( bikes and 4-wheelers mostly) that is used to offset the effects of the ethanol but I can't specificaly remember the name since I don't use it. If I can remember I'll try to post it.

 

Thanks,
I'm showing no fault codes on the computer and they were supposedly just changed by the dealership when it last went in with the check Eng light. So I'll leave tham alone. I'l try the MMO in my next tank of gas. We'll see what happens.
So far she's doing okay.

 

Does NY require 10% ethanol? If they don't, try to find a pump that has 100% gas. You may have to buy premium, but it will help you figure out if the "corn" is really hurting you.

 

NY uses 10% ethanol in winter, and then switches back to summer blend with I believe is less than 5% ethanol. It may be 100% gasoline.
I think they just switched over too, cause my Silverado was getting 15 mpg's all winter, but it's back up to 17 now.

 

I do get a little better milage with 93 octane (2-3 mpg), but is it worth spending the extra $$$ on a regular basis? Is higher octane better for the motor?

 

No, unless it is pinging on lower octane. Lower octane fuel is just as good if the timing doesn't change.

Now having said that, E10 is not good, it is/was pushed along side "global warming" to make the Earth happy. You say 2-3mpg boost in mpg? 10% of 20mpg is 2mpg. That's the amount of ethanol in your gas. New engines usually pull timing (retard) in order to run 87 with E10. Theoretically, it should run the same timing as 100% gas, but it doesn't. Less timing=less power.

If your Premium is more than eh 15% more expensive, don't buy it. If it is less than say 10% more, buy it. If it is in the middle, you be the judge. That is assuming your Premium is 100% gas, if it is E10, buy 87. If the mid grade gas doesn't contain ethanol, and the other two do, buy the mid.

Cliffnotes:
Always buy 87 if it is 100% gasoline. Buy 87 E10 if both 87 and Premium contain ethanol. Buy Premium when it is <12% more than 87 (assuming the 87 is E10 and the Premium is 100%)

Baby cliffnotes:
Avoid ethanol. If you have no choice, buy E10 87/Regular.

 

Octane is the fuels resistance to knock. Using higher octane than what the engine is designed for can actually shorten the life of the motor.
Always use the recommended octane that the engine was designed for.

 

Do you have any proof of this?

 

The octane rating actually refers to the speed at which the fuel is burned. Higher octane = slower. CSCustom is correct by stating that the octane rating is a fuels resistance to knock, but another way to say it is the fuel's resistance to predetonation, which produces the knocking/pinging sounds we've all grown to love. More ignition timing increases the likelihood of knocking, so higher octane is necessary to slow the burn of the fuel so the combustion occurs where it's meant to, not in your intake runners. A stock engine, be it a 2.5, 3.9, 5.2, or 5.9 or a newer generation 4.7 or 3.7 will not benefit from using premium gas other than maybe a small MPG increase that probably won't offset the extra cost of the gas. If you have modified your timing in some way (custom flash, programmer, MP PCM) then you may have to run premium. Otherwise, stick to the ol' 87 and save your cash for something fun... like beer!

decent explanation of octane here: http://www.answers.com/topic/petrol

- miggity

 

I never said buy 100% Premium if 100% Regular was available.