[gone-ot]

Originally Posted by oil pan 4

http://www.ethanol.org/pdf/contentmg...inal_12507.pdf

Ethanol mixes of 25% to 35% seems to increase fuel economy in certian vehicles.

...but, those "improvements" are actually predicated upon the ECM's ability to first detect, then compensate for, the changes in ethanol content in the gasoline. Some ECM's handle this process using Knock Retard (KR) others do it differently. It comes down to the "smartness" of the engine electronics, sensors and computer software.