manual vs. automatic

[Yaris Hilton]

Originally Posted by jhsouders

Seeing as this came up, as you know ethanol reduces fuel efficiency, so up to 10% ethanol can hurt your mileage by around 10%.

No, it doesn't equate to that at all. E10 gasoline has about 3.4% less energy per gallon than "pure" gasoline. That's about how much your mileage will drop.

"Pure" gasoline hasn't been around for a lot longer than the ~4 years since E10 became the standard. Before that, most gasoline sold in the U.S. had ~15% methyl t-butyl ether (MTBE) in it. There are a number of other oxygenates that were used, like TAME (t-amyl methyl ether), diisopropyl ether, isopropyl alcohol, t-butyl alcohol, methanol, etc. The market for them has really been hit hard by the mandates pushed through by the ethanol lobby. If you get the raw gasoline pumped through the pipelines before it's had the oxygenates added, you'll get something that's about 2-4 octane numbers lower than the ethanol blended stuff. That will make your engine retard its spark timing and run less efficiently.

There's a lot to criticize about growing corn to make motor fuel out of. But the "true believers" in the harmful effects of fuel ethanol are pretty much deluded.