Ethanol
The ethanol content and octane rating are two different things. Most gasoline here is sold with 10 percent ethanol (E10), and I have yet to see any unleaded gasoline without it anywhere in this area.
Octane ratings range from 87 for regular to 92 or 93 for most premium unleaded around here. Most stations also sell a "mid-grade" fuel with an octane rating of 89. All have 10 percent ethanol.
Ethanol (ethyl alcohol) has a very high "octane" rating itself and would be great for racing applications or very high compression ratios & advanced ignition timing. However, alcohol has far fewer BTUs than gasoline; thus negatively affecting your fuel economy.
In PA, they sell E85 (85 percent ethanol and 15 percent gasoline) for about sixty cents a gallon less than regular unleaded.......but your fuel economy suffers significantly. It is a wash at best, I suppose; and only "flex fuel" vehicles can run on E85. It will destroy a 'regular car' in short order.
Stick to 100 percent gasoline if it is available in your market!
