Hybrid-electric vehicles (HEVs) like the popular Toyota Prius combine fuel and emission-reducing technology of the electric vehicle with the typical comforts and familiarity of a gasoline-based automobile. The main components of a hybrid-electric car are the electric motor, gasoline motor and energy storage technology in the form of batteries and a gasoline tank. The added efficiency of using the hybrid power drive allows modern hybrid cars to go up to 500 miles on a single fill up.
The electric motor is utilized in a typical parallel hybrid car for idling and low speeds around town. The electric motor's fuel source is the battery bank, which is recharged both by the gasoline engine when engaged and systems like regenerative braking that capture the kinetic energy in braking to recharge the batteries. Newer hybrids called plug-in hybrids will be able to charge by connecting directly to an electrical outlet.
The gasoline engine in a hybrid car works similarly to a non-hybrid except that it is not always engaged. A computer in the car will determine when the gas engine needs to be used and turn it on automatically (usually at higher speeds). The gas-electric power system and the energy storage sources are integrated in the hybrid vehicle to strike a balance between performance and fuel economy.