Isocetane (2,2,4,4,6,8,8-heptamethylnonane) is a highly branched alkane used as a reference in determining the cetane number of diesel.
As a highly branched alkane, isocetane (2,2,4,4,6,8,8-heptamethylnonane) is employed as a standard for evaluating the cetane number in diesel fuel formulations.