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Discussion Starter #1
Just have a question for current owners regarding petrol and octane levels. My understanding is that the 12C requires octane levels of 91-93 for best performance. In North America most premium fuels are 91 octane and some of the ones I know have 94 but that is because 10% of it is ethanol to boost the octane level. Is 10% ethanol allowed to be used in the 12C or not? I know in some brand vehicles any amount ethanol is not recommended because they use plastic injectors which can get ruined by ethanol.
 

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North America have different rating for fuel with rest of the world

mac4lyf

You misunderstand the rating of fuel in US/Canada at the pump. The "octane" rating you see is the AKI (Anti-Knock Index). It is about 4-5 points below Europe Octane rating. Europe octane 92 fuel is the same as US 87 fuel. Most car labeling for North America will reflect that if you look at the fuel door. Premium fuel with rating of 94+ in North America is almost like race fuel. No one need that for DD, I only use that when I am going to the track.

I personally will not use E10 fuel if I can help it, not for the reason that you are thinking. Almost all modern engine/parts can use E10 fuel with no problem. I dont use E10 because I don't drive enough. I dont think I refuel the tank once per month per car. :p E10 fuel should not be in your tank for more than 2-3 weeks depending on how busy the gas station you bought your fuel from. Ethanol will absorb any water in tank (yours or the station) and moisture from the air. This happens quickly and will actually lower your overall octane level by up to 15 points. So, an older (3-4weeks) E10 fuel with octane level of 94 is like running your engine with octane 80 fuel because of the water in the fuel. We all know it is not good to have water in the engine. E10 fuel also lead to faster fuel separation. I have a choice where I am from and I dont have to buy E10 fuel. Some states only have E10 fuel. Remember E10 was introduce to "decreasing US dependence on foreign oil" and to provide a subsidizes to the farmer. It wasnt put in place to help the car owners. A non E10 fuel with same octane rating as an E10 will be more expensive. If you must use E10 fuel, use it quickly.
 

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mac4lyf

You misunderstand the rating of fuel in US/Canada at the pump. The "octane" rating you see is the AKI (Anti-Knock Index). It is about 4-5 points below Europe Octane rating. Europe octane 92 fuel is the same as US 87 fuel. Most car labeling for North America will reflect that if you look at the fuel door. Premium fuel with rating of 94+ in North America is almost like race fuel. No one need that for DD, I only use that when I am going to the track.

I personally will not use E10 fuel if I can help it, not for the reason that you are thinking. Almost all modern engine/parts can use E10 fuel with no problem. I dont use E10 because I don't drive enough. I dont think I refuel the tank once per month per car. :p E10 fuel should not be in your tank for more than 2-3 weeks depending on how busy the gas station you bought your fuel from. Ethanol will absorb any water in tank (yours or the station) and moisture from the air. This happens quickly and will actually lower your overall octane level by up to 15 points. So, an older (3-4weeks) E10 fuel with octane level of 94 is like running your engine with octane 80 fuel because of the water in the fuel. We all know it is not good to have water in the engine. E10 fuel also lead to faster fuel separation. I have a choice where I am from and I dont have to buy E10 fuel. Some states only have E10 fuel. Remember E10 was introduce to "decreasing US dependence on foreign oil" and to provide a subsidizes to the farmer. It wasnt put in place to help the car owners. A non E10 fuel with same octane rating as an E10 will be more expensive. If you must use E10 fuel, use it quickly.
What do you think would be the power difference between 94 octane (with up to 10% ethanol) vs. 91 octane (ethanol free)? Assuming the 94 is always fresh and used quickly.
 

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Hmm. It all depends. In a perfect setup (you mixed your own E10), 94 octane E10 will have more horsepower than 91 octane (even 94) ethanol free. The increase of horsepower is from how the fuel burn in your engine (it combusted faster at more TDC). It lower your fuel mileage but only at about 3-4 percent. But and a big BUT. All this only apply when you have a tuned car (perfect fuel, perfect tire, Dino engine). When you buy E10 from the gas station, you dont know the content of the ethanol, it could be 8-12% and you dont know the water content. The oil company mixed the ethanol level depending on weather (higher during summer and lower during winter). Just like me using 94+ ethanol free fuel on race day. I know it will not make me go faster (ok, maybe that 0.00001 sec). It just make me think that I will go faster :D
 

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Discussion Starter #6
mac4lyf

You misunderstand the rating of fuel in US/Canada at the pump. The "octane" rating you see is the AKI (Anti-Knock Index). It is about 4-5 points below Europe Octane rating. Europe octane 92 fuel is the same as US 87 fuel. Most car labeling for North America will reflect that if you look at the fuel door. Premium fuel with rating of 94+ in North America is almost like race fuel. No one need that for DD, I only use that when I am going to the track.

I personally will not use E10 fuel if I can help it, not for the reason that you are thinking. Almost all modern engine/parts can use E10 fuel with no problem. I dont use E10 because I don't drive enough. I dont think I refuel the tank once per month per car. :p E10 fuel should not be in your tank for more than 2-3 weeks depending on how busy the gas station you bought your fuel from. Ethanol will absorb any water in tank (yours or the station) and moisture from the air. This happens quickly and will actually lower your overall octane level by up to 15 points. So, an older (3-4weeks) E10 fuel with octane level of 94 is like running your engine with octane 80 fuel because of the water in the fuel. We all know it is not good to have water in the engine. E10 fuel also lead to faster fuel separation. I have a choice where I am from and I dont have to buy E10 fuel. Some states only have E10 fuel. Remember E10 was introduce to "decreasing US dependence on foreign oil" and to provide a subsidizes to the farmer. It wasnt put in place to help the car owners. A non E10 fuel with same octane rating as an E10 will be more expensive. If you must use E10 fuel, use it quickly.

Thank you for the info!!
 

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Discussion Starter #7
What do you think would be the power difference between 94 octane (with up to 10% ethanol) vs. 91 octane (ethanol free)? Assuming the 94 is always fresh and used quickly.

As MacMP12 had stated which corresponds with this site from a professional engineer... this guy states you could get up to 10% increase in power and torque depending on the engine
http://www.fuelsaving.info/fuels.htm
 
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