Systems and methods for determining indicated mean effective pressure

An engine control system of a vehicle includes a cylinder control module configured to: determine a target sequence for at least activating and deactivating cylinders of an engine based on a torque request; and activate and deactivate the cylinders of the engine according to the target sequence. A values module is configured to determine, based on the target sequence, a plurality of coefficients and an offset value. An indicated mean effective pressure (IMEP) determination module is configured to determine an IMEP of a first cylinder based on: the plurality of coefficients; the offset value; and a plurality of engine speeds at a predetermined crankshaft positions, respectively.