Calculated Carbon Aromacity Index.
The CCAI is a calculated value originally intended to indicate the ignition properties or ignition delay of the fuel related to the viscosity and density. The CCAI gives no indication of the combustion properties. The CCAI limit is useful to measure fuels with unusual density and viscosity relations.
More tests are available that are can find the ignition and combustion properties and these can be helpful to examine the performance of the fuels.