This paper is a continuation of work previously discussed in SAE 2014-01-0179 and SAE 2015-01-0805, which is targeted at the progress of further improving the capability, precision, and durability of the Ignition Quality Tester (IQT™) and associated ASTM D6890/EN15195 Test Methods. The results presented in those two papers indicated how the new generation of IQT™ with the TALM Precision Package (TALM-IQT™) upgrade can markedly improve the precision of the ASTM D6890 and CEN EN 15195 Derived Cetane Number (DCN) test methods. This paper will evaluate the performance of the upgraded instruments over the past 20 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 all four ASTM Cetane Number (CN) and Derived Cetane Number (DCN) standard test methods that participated meaningfully in the ASTM NEG diesel fuel exchange program. 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 ASTM NEG fuel exchange program’s monthly reports strongly support the findings of the two previous SAE papers. This paper shows that the ASTM D6890/EN15195 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.