The combined energy of a dynamic electric motor, powered by a state-of-the-art lithium-ion battery, and the 2.0L Atkinson-cycle I-4 gas engine supplies the power for the C-MAX Hybrid. When needed, the gas engine kicks in as the main energy source, providing extra power for actions such as passing or merging. The gas engine and the electric motor work together to deliver maximum horsepower. The C-MAX Hybrid battery uses an air-cooling system to regulate battery temperature and help maximize battery life. All of this adds up to impressive efficiency and power.