Ignition Quality Determination Problems with Alternative Fuels for Compression Ignition Engines

Using cetane numbers to describe the ignition characteristics of fuels has proved to be most unsatisfactory when testing alternative fuels for diesel engines. Selected test results show that existing methods of determining cetane numbers, not only below the measurement range of standardized cetane rating engines, produce very dubious results, and that cetane numbers fail to achieve their original purpose in that they need by no means be representative of the ignition characteristics of a fuel in the practical diesel engine. The partly extreme discrepancies demonstrate the need to develop and standardize new or modified test procedures suitable for the whole range of potential diesel fuels.