Combustion engine with high compression ratio and method for its operation

The engine has a piston (2) movable to and fro between upper and lower dead centers (OT, UT), where a compression ratio of the engine is determined by quotients of a space of a cylinder (1) and a combustion space, and lies in a range from 15:1 to 22:1. A valve control device e.g. cam shaft, is configured such that an inlet valve (7) closes a crankshaft angle ranging between 80 degree and 120 degree in the upper dead center in a suction cycle, and piston movement is continued upto the lower dead center when the inlet valve is closed for producing low pressure in a cylinder space. An independent claim is also included for a method for operating an internal combustion engine.