  The performance of quantum heat engines is generally based on the analysis of
a single cycle. We challenge this approach by showing that the total work
performed by a quantum engine need not be proportional to the number of cycles.
Furthermore, optimizing the engine over multiple cycles leads to the
identification of scenarios with a quantum enhancement. We demonstrate our
findings with a quantum Otto engine based on a two-level system as the working
substance that supplies power to an external oscillator.
