Abstract: A combustion engine (1) of the piston engine type where the static compression ratio exceeds approximately 15:1, especially in the range of from approximately 15:1 to approximately 20:1, preferably approximately 17:1. The engine is provided with an ignition system (3) where the ignition point is situated after the top dead center (TDC), especially in the range of from approxmiately 0.degree. TDC to approximately 20.degree. TDC, preferably approximately 4.degree. TDC. As a result, it is possible to achieve an ignition of a fuel, the spontaneous ignition capacity of which at the predetermined compression ratio does not usually suffize. The resulting ignition generates a maximum pressure in the cylinder of approximately 90.degree. TDC, whereby a high efficiency of the fuel is obtained without simultaneously involving a steep increase in the temperature in the combustion chamber.