Cetane Index - ASTM D4737 (improved)

ASTM D4737 improved 4-variable Cetane Index formula (preferred over D976 for regulatory use).

CetaneD4737Distillate

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

CI = 45.2 + 0.0892 T_{10} + (0.131 + 0.901\Delta D) T_{50} + (0.0523 - 0.42\Delta D) T_{90}

Symbol	Meaning	Unit
$T_{10}, T_{50}, T_{90}$	Distillation recovery temperatures	°C
$D$	Density @ 15 °C	g/ml

Source: ASTM D4737

ASTM D4737 improved 4-variable Cetane Index formula (preferred over D976 for regulatory use).