The Calculated Carbon Aromaticity Index (CCAI) is an index of the ignition quality of a residual fuel oil. It is calculated from the density, kinematic viscosity and viscosity temperature of the residual fuel oil in question.
| Density 15°C (kg/cbm) | |
| Kinematic Viscosity (cST) | |
| Viscosity Temperature (°C) | |
| CCAI |
Remark: Ignition performance requirements of residual fuels in the marine diesel engines are primarily determined by engine type and more significantly, by engine operating conditions fuel factors influence ignition characteristics to much lesser extent. For this reason no general limits for the ignition quality can be applied, since a value which may be problematical to one engine under adverse conditions may perform quite satisfactorily in many other instances. If required, further guidance on acceptable ignition quality should be obtained from the engine manufacturer.