This paper is a continuation of work previously discussed in SAE 2014-01-0179  and SAE 2015-01-0805 , which was intended to improve the capability and precision of the Ignition Quality Tester (IQT™) and associated ASTM D6890 /CEN EN 15195 /EI IP 498  Test Methods. The results presented in those two papers indicated how the new generation of IQT™ with the TALM Precision Package upgrade can markedly improve the precision of the ASTM D6890, CEN EN 15195 and EI IP 498 Derived Cetane Number (DCN) test methods.This paper will evaluate the performance of the upgraded instruments over the past 21 months of their participation in ASTM’s National Fuel Exchange Group (NEG) diesel fuel exchange program. It will also present a comparison of the published precision of the ASTM Cetane Number (CN) and Derived Cetane Number (DCN) standard test methods that participated meaningfully in the ASTM NEG diesel fuel exchange program (ASTM D613 /CEN EN ISO 5165 /EI IP 41  and ASTM D6890 ). In addition, it will present and discuss a comparison between the precision of these ASTM standard methods, the mini Inter-Laboratory Study presented in SAE 2015-01-0805  and the recent test results from the ASTM NEG fuel exchange program (real world data).The real world results extracted from the NEG fuel exchange program’s monthly reports strongly support the findings of the two previous SAE papers. This paper shows that the D6890/EN 15195/IP 498 instruments equipped with the TALM Precision Package have clearly demonstrated a marked improvement in precision of the ASTM D6890 and CEN EN 15195 Test Methods.