The paper deals with the numerical simulation of a HCCI engine. The OBEH (Cycle) code has been used as the basis for a complex modeling of a turbocharged HCCI engine. An influence of fuel ignition properties, i.e., fuel cetane number, on the engine cycle has been examined. Fuel ignition properties have been solved using chemical kinetics applied to the full reaction scheme. Iso-octane, n-heptane and DME have been considered in the work presented. (en)