Reciprocating piston engine

A system comprising:

• a reciprocating-piston engine, being a 4-stroke engine for driving a vehicle and comprising a crankshaft;
• an electrical control unit;
• and
• a crankshaft sensor for detecting a position of the crankshaft,
• wherein
• the reciprocating-piston engine has an electrically actuatable variable outlet valve drive for at least one first outlet valve which is assigned to a first combustion chamber of a first piston, said electrically actuatable variable outlet valve drive being designed such that the at least one first outlet valve can be opened regardless of the position of the crankshaft, the reciprocating-piston engine has an electrically actuatable variable inlet valve drive for at least one first inlet valve which is assigned to the first combustion chamber, said electrically actuatable variable inlet valve drive being designed such that the at least one first inlet valve can be opened regardless of the position of the crankshaft,
• the control unit is designed such that switching between a first operating mode, in which the crankshaft is being driven with combustion engine action, and a second operating mode, in which the crankshaft is being driven without combustion engine action, is performed, wherein the switching is performed in a manner dependent on an electronic accelerator pedal signal and/or in a manner dependent on a crankshaft rotational speed signal or on a time-dependent basis or after a certain number of rotations of the crankshaft, and
• the control unit is interconnected with the crankshaft sensor, with the variable inlet valve drive and with the variable outlet valve drive, and designed, such that, in the first operating mode, the inlet valve drive and the outlet valve drive run in 4-stroke operation of the reciprocating-piston engine, and in the second operating mode, the inlet valve drive and the outlet valve drive run in 2-stroke operation of the reciprocating-piston engine, wherein in said 2-stroke operation
• the at least one first inlet valve is opened in a position range of the crankshaft in which the first piston moves away from the at least one first inlet valve and
• the at least one first outlet valve is opened in a position range of the crankshaft in which the first piston moves toward the at least one first outlet valve.