One embodiment is a method of operating an electronic control system (ECS) to control an engine to propel a vehicle. The method comprises receiving a throttle command, determining an operation to increase engine cycle efficiency by reducing engine torque below a magnitude corresponding to the throttle command and below a torque curve limit over a first vehicle operation segment and permitting an increase in engine torque above the torque curve limit over a second vehicle operation segment, controlling the engine to output torque below the magnitude corresponding to the throttle command and below the torque curve limit over the first vehicle operation segment, and controlling the engine to output torque above the torque curve limit over the second vehicle operation segment in response to a second received throttle command and constrained by an extended limit on operation of the engine above the torque curve limit.