[soutthpaw]

Jack,
Ya beat me to it as usual.. but you are correct about octane ratings. it is purely for preventing pre-detonation of the fuel. END OF STORY! it doesn't do anything else. Here is Colorado our regular gas is 85 not 87 octane but can be used as 87 becase when you are a mile or more high in altitude the oxygen in the air is less so that is a natural inhibitor of combustion.. E85 requires about 15 to 20% more fuel to go the same distance or produce the same power. and thus you will see your E85 mpg drop by 15 to 20 % so unless the gas is more than 15% to 20% Less expensive that regular gas you are not saving anything... locally to me its only about 20 to 40 cents a gallon cheaper than regular gas