cetane number for additized diesel fuels. Diesel engine operation is primarily related to the actual cetane number and the cetane index is simply an estimation of the base (unadditized) cetane number. Industry standards The industry standards for measuring cetane number are ASTM D613 (ISO 5165) for the CFR engine, D6890 for the IQT, and D7170 for the FIT. See also NExBTL Octane rating References Further reading External links Article by Bruce Hamilton Explanation of Cetane from BP Diesel fuel Fuel technology Petroleum production Scales