A lean combustion method for a four-stroke reciprocating internal combustion engine with a cylinder in which a combustion chamber is delimited by a cylinder head and a piston which is movable in reciprocating manner, the volume of which chamber can be altered by the piston and wherein a fuel can be introduced directly into the combustion chamber, wherein at least one gas exchange inlet valve and one gas exchange outlet valve are provided for a charge cycle, and wherein an intermediate compression can be set in the combustion chamber at a charge cycle top dead centre (LWOT) and a main compression can be set at an ignition top dead centre, having the following method steps after an expansion phase: - closing the gas exchange outlet valve before LWOT; - introducing a pilot quantity of fuel in the intermediate compression up to at the latest the LWOT and compressing the pilot quantity of the fuel and a residual exhaust in the cylinder to form intermediate products (CH 2 O, H 2 O 2, CO, C 2 H 4, C 3 H 4, etc.) and complete combustion products (CO 2, H 2 O); - opening the gas exchange inlet valve after LWOT and introducing a fresh gas in an intake phase into the combustion chamber; - introducing a main quantity of a fuel into the combustion chamber during the intake phase and/or the main compression phase, and closing the gas exchange inlet valve; - compressing the fresh gas and the fuel in the main compression phase; - igniting a mixture of fresh gas and fuel formed in the combustion chamber; - expanding, opening the gas exchange outlet valve and expelling an exhaust gas formed by a combustion, in the expansion phase; characterised by a controlled conversion of the pilot quantity of the fuel into the intermediate products and into the complete combustion products (CO 2, H 2 O) by the method steps that - a maximum intermediate compression temperature can be set by varying the time of closing of the gas exchange outlet valve and/or - a maximum intermediate compression temperature can be set by varying the time of opening of the gas exchange inlet valve before LWOT, and - the mass of the pilot quantity of the fuel is variable, - the introduction of the pilot quantity of the fuel taking place immediately after the closing of the gas exchange outlet valve, and - the pilot quantity of fuel being at most 50% of a total quantity of fuel, - closing the gas exchange outlet valve before LWOT; - introducing a pilot quantity of fuel in the intermediate compression up to at the latest the LWOT and compressing the pilot quantity of the fuel and a residual exhaust in the cylinder to form intermediate products (CH 2 O, H 2 O 2, CO, C 2 H 4, C 3 H 4, etc.) and complete combustion products (CO 2, H 2 O); - opening the gas exchange inlet valve after LWOT and introducing a fresh gas in an intake phase into the combustion chamber; - introducing a main quantity of a fuel into the combustion chamber during the intake phase and/or the main compression phase, and closing the gas exchange inlet valve; - compressing the fresh gas and the fuel in the main compression phase; - igniting a mixture of fresh gas and fuel formed in the combustion chamber; - expanding, opening the gas exchange outlet valve and expelling an exhaust gas formed by a combustion, in the expansion phase; - a maximum intermediate compression temperature can be set by varying the time of closing of the gas exchange outlet valve and/or - a maximum intermediate compression temperature can be set by varying the time of opening of the gas exchange inlet valve before LWOT, and - the mass of the pilot quantity of the fuel is variable, - the introduction of the pilot quantity of the fuel taking place immediately after the closing of the gas exchange outlet valve, and - the pilot quantity of fuel being at most 50% of a total quantity of fuel,