JJuday
Addicted to ArboristSite
Octane has nothing to do with the compresion ratios (pure octane has a rating of 100 and is a chemical in gasoline). It is a measure of a fuels resistance to compression induced ignition (pinging, dieseling) Fuel that is E10 and rated at 89 octane is still 89 octane its just that the base fuel without the ethanol started out at a lower octane rating.
Higher ethanol content means your engine needs more fuel to run properly but loses power due to ethanols lower energy content so you not only lose power but fuel efficiency. Ethanol also seperates out when it pulls in enough atmospheric moisture which leaves you stuck with a puddle of water in the bottom of your tank as well as a lower octane base stock.
Yes, octane has everything to do with compression ratios and how an engine will perform. You mean to tell me that running unleaded in a Diesel engine is not going to have a thing to do with how compressible that fuel is??? Or octane rating. The higher the octane the higher the compression ratio needs to be in order to get optimum combustion. There is a certian point when an engines performance is directly impacted by it's own compression ratio and how compressible it's fuel is. This is one reason why there are flex-fuel vehicles that run on E-85 and when they have no E-85 available they have to be run on premium. Anything much above E-10 will cause spark knock in regular engines, or imcomplete detonation, dieseling ect.
What I meant is that adding a 10% ratio of ethyl alcohol to gas can increase the octane rating by 2-3 points.