View Single Post
Old 03-16-2010, 05:20 PM   #5 (permalink)
Master EcoModder
Join Date: Nov 2008
Location: Madison AL
Posts: 1,123

The Geo - '93 Geo Metro
Team Metro
90 day: 45.16 mpg (US)
Thanks: 30
Thanked 40 Times in 37 Posts
Originally Posted by Old Tele man View Post, the real answer may lie in what year vehicle the guy was talking about--pre-electronics carburation, OBDI or todays' OBDII?
We're talking about OBDII.

This is pretty much the conversation we have been having about it. (the last 2-3 posts)

Originally Posted by CSCustomCars View Post
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.
Originally Posted by Cas161 View Post
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?
Originally Posted by MadisonDakota View Post
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.

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.
Does everybody get it?
  Reply With Quote