An accessory load control system for a vehicle, includes an actuator control module, a period estimation module, and a load control module. The actuator control module operates an internal combustion engine of the vehicle in a high-efficiency (HE) mode. The period estimation module estimates a period between a current time and a future time when an actual load on a crankshaft of the engine will reach a maximum engine load associated with the HE mode. The load control module selectively decreases engine loads applied by vehicle accessories, respectively, based on the period.