We perform the first study of holographic heat engines where the working material is a rotating black hole, obtaining exact results for the efficiency of a rectangular engine cycle. We also make general considerations in the context of benchmarking these engines on circular cycles. We find an exact expression that is valid for black holes with vanishing specific heat at constant volume and derive an upper bound, below the Carnot efficiency and independent of spacetime dimension, which holds for any black hole of this kind. We illustrate our results with applications to a variety of black holes, noting the effects of spacetime dimension, rotation, and higher curvature corrections on the efficiency of the cycle.

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We investigate a holographic version of Maxwell's equal area law analogous to that for the phase transition in the black hole temperature/black hole entropy plane of a charged AdS black hole. We consider proposed area laws for both the black hole temperature/holographic entanglement entropy plane and the black hole temperature/2-point correlation function plane. Despite recent claims to the contrary, we demonstrate numerically that neither proposal is valid. We argue that there is no physical reason to expect such a construction in these planes.