A hybrid electric vehicle includes an intelligent vehicle controller, an electric motor, a battery, an internal combustion engine (ICE), and an electrical generator coupled to the ICE configured to provide electricity to the battery and the electric motor. The intelligent vehicle controller receives ICE power level shifting data from the electrical generator, ICE, battery, and electric motor. The intelligent vehicle controller determines a desirable torque and/or a desirable revolutions per minute (RPM) for the ICE based on the received ICE power level shifting data by utilizing an efficiency map that includes fuel efficiency contours and noise, vibration, and/or harshness (NVH) level lines for the hybrid electric vehicle. The intelligent vehicle controller may have first and second vehicle operation modes, and may derive first and a second desirable power levels for the ICE in the first and second operation modes, based on the ICE power level shifting data.