DIESEL FUEL CETANE INDEX CHANGE
The ASTM cetane index test D–4737 attempts to measure the real content of the cetane in diesel fuel by measuring the density and the distillation points of an unadulterated fuel. Additives can effect the measurement of cetane by manipulating the density and boiling point numbers, in effect, influencing the cetane values artificially. Since the FFC is not in any way an additive, that is it does not dissolve in the sample, it cannot ‘fool’ the ASTM index test.
The best fuels for diesel and jet engines are composed of long chain aliphatic hydrocarbon molecules also called alkanes. These are described in Fuels and Lubricants Handbook, George E. Totten, Ed., ASTM, 2003.