Does gasoline enriched with ethanol burn hotter?
No. Even though ethanol has a higher octane rating than gasoline, it has less carbon and more oxygen than gas. As a result of the carbon and oxygen content, your engine will burn cooler on E85. A gallon of 10 percent ethanol-enriched gasoline contains about 112,000 BTU of heat energy, compared to 114,000 BTU for straight gasoline.
