Wow all is all i have to say about that article?? Im not sure how long the person that wrote it spent in a mechanics shop but obviously he didnt pick up much common sense while he was there. He did manage to get a few facts correct but left out important details.
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The relationship between Cetane and Octane is in direct relationship to both fuels propensity to detonate. Cetane as stated shows how readily diesel will detonate when injected into the combustion chamber. On a Diesel engine diesel is injected at or around the top of the compression stroke (thus the reason a mechanical fuel pump had to be used on older diesel engines to create the high pressure needed to inject into a cylinder under pressure.) If diesel was mixed with the air charge before compression you would have detonation prior to Top Dead Center (TDC). If that happens i can cause major damage to the engine. most diesel engines run a compression ratio of between 13:1 to 17:1. The Cetane rating shows the readiness of diesel to detonate at these compression ratios.
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Octane as stated is the resistance of gasoline to detonation. But where the author went wrong was that gasoline actually combusts/detonates more easily then diesel. The reason we have 3 octane ratings at most US pumps is because most gasoline engines operate with compression ratios of between 8.5:1 to 10.3:1 and gasoline is mixed with the air charge prior to compression, this creates the need to avoid Detonation till the spark plug fires. Therefore the need for multiple fuels to be formulated as close to the detonation point of a particular compression as possible.
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If gasoline had a cetane rating it would be lower then diesel and conversely if diesel had a octane rating it would be higher then gasoline. The reason that diesel engines dont need to avoid detonation and actually promote it. Is because of when the fuel is added to the engine. Coincidentally Engine manufactures are starting to use a method similar to that used by diesel engines to inject fuel into the engines, Called GDI or Gasoline Direct Injection this has the added advantage of being able to run leaner fuel to air ratios, thus improving fuel economy and decreasing air polutants.
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Prior to the removal of leaded gasoline it wasnt uncommon to see cars running on pump gas at 11.5:1 or slightly higher compression ratios these cars could have run on diesel but very poorly. There are several miltary examples of high compression engines that ran on both diesel and gasoline along with several other fuels. Adding diesel to gasoline would have the effect of raising the octane rating of the gasoline. Thus allowing a slower burning longer power stroke. Diesels Create more torque because thier fuel burns slower and longer. Gasoline engines tend to actually pulse which creates the need for more cylinders to create a smoother running engine.
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The reason for the damage to diesel engines when runnning on gasoline isnt because it doesnt burn it is because it burns to fast and hot. Gasoline actually burns much hotter then diesel. Diesel engines actually run cooler then comparable horsepower Gasoline engines. The most common damage to a diesel engines when they have run gasoline is the ejection of one or more injectors from the head. This is because of the Explosive detonation of gasoline when ignited by compression alone.
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I have not been able to find any actually studies of the benifits of adding small amounts of diesel to gasoline engines. But a can say from personal experiance that it increased my HP/Torque and fuel economy by how much i cannot be specific its been to long since i conducted the tests and have moved several times since. I added between 3/4 to 1 gallon of diesel to 18gallons of gasoline.