Annex E of ISO 8217 - cetane-number proxy for ultra-low-sulphur distillates (DMA, DMB, DFA, DMZ) when the CFR engine cetane test is not available.
Formula
$$ ECN = -386.26 + 0.174 \rho_{15} + 141.59 \log \nu_{40} + 1.13 \cdot 10^{-5} \rho_{15}^2 - 19.64 (\log \nu_{40})^2 $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $\rho_{15}$ | Density at 15 °C | kg/m³ | BDN |
| $\nu_{40}$ | Viscosity at 40 °C | cSt | BDN |
| $ECN$ | Estimated Cetane Number | - | result |
Sources
- ISO 8217 Annex E.