Cetane Index (ASTM D976)
Estimate cetane index from density and mid-boiling point (T50) - the lab proxy for actual cetane number on distillate fuels.
Cetane Index
59.8 -
Formula, assumptions, and limits
ASTM D976 single-variable fit, older and simpler than the D4737 four-variable equation. Distillate MGO/MDO typically CI 45–52.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Specific gravity at 60 °F | - | derived from API | |
| Mid-boiling point at 50 % recovery | °F | ASTM D86 / D2887 | |
| Cetane Index | - | result |