986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Ethanol Free vs Ethanol Gas: Does it affect performance

JFP in PA · 09-10-2016, 06:15 AM

Here are the bottom lines: A given volume of ethanol contains about 80,000 BTU's of energy. The same volume of gasoline contains 118,000 BTU's of energy. So ETOH contains about 1/3 less energy per volume of fuel. Contrary to popular belief, higher octane does not equate to more power or more energy contained in a gallon of gas. Octane inhibits gasolines ability to burn. Higher octane gas is better suited for higher compression engines prone to detonation. Since ethanol contains less energy per gallon, you have to add more fuel to do the same amount of work. Bottom line, if you burn gas with no ethanol, you will see 5-8% better fuel economy (less gas burned to do the same amount of work) and about a 3-5% increase in horsepower (on a dyno).

09-10-2016, 06:15 AM	#12
JFP in PA Registered User Join Date: Feb 2005 Location: It's a kind of magic..... Posts: 6,614	Here are the bottom lines: A given volume of ethanol contains about 80,000 BTU's of energy. The same volume of gasoline contains 118,000 BTU's of energy. So ETOH contains about 1/3 less energy per volume of fuel. Contrary to popular belief, higher octane does not equate to more power or more energy contained in a gallon of gas. Octane inhibits gasolines ability to burn. Higher octane gas is better suited for higher compression engines prone to detonation. Since ethanol contains less energy per gallon, you have to add more fuel to do the same amount of work. Bottom line, if you burn gas with no ethanol, you will see 5-8% better fuel economy (less gas burned to do the same amount of work) and about a 3-5% increase in horsepower (on a dyno). __________________ “Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein Last edited by JFP in PA; 09-10-2016 at 06:41 AM.