Hybrid engines combine two power sources, typically an internal combustion engine and an electric motor. This design allows vehicles to use fuel more efficiently, reducing emissions and improving fuel economy. The electric motor can assist the engine during acceleration or operate independently at low speeds, making driving smoother and quieter. These engines are commonly found in hybrid vehicles, which can switch between or combine both power sources. This technology not only helps in conserving energy but also contributes to a decrease in reliance on fossil fuels. Popular examples include the Toyota Prius and Honda Insight.