Components of a Hybrid Electric Vehicle

A hybrid, also known as a hybrid-electric vehicle (or HEV), combines a gasoline engine with a battery-powered electric motor to increase fuel efficiency. Hybrids typically store energy created by the car's motion into the battery, and the electrical engine provides a power boost during acceleration, lane passing or hills. Hybrid cars typically do not idle, and instead shut on and off automatically when the car stops and goes, thus conserving energy.

Of the hybrids currently in the market, there are two types: full and mild. Both the gasoline engine and electric motor power the wheels of a full hybrid, which allows the gasoline engine to shut off when the car idles. Toyota, Lexus and Ford use the full-hybrid technology. In mild hybrids, the electric motor boosts the gasoline engine when it needs more power, resulting in the automatic shut-on/shut-off feature recognized in some hybrids. General Motors is most known for using mild hybrid technology.

Kinetic energy, or the energy of motion, is used to keep the electric battery charged on the hybrid. When the driver uses the brakes, this sends a charge to the car's battery. Some hybrids garner energy from the gasoline engine by attaching a spinning electrical generator on the device. Contrary to myth, hybrid vehicles do not need to be plugged in for the battery to be fully charged. Batteries are designed to last the entire life of the vehicle, or 150,000 to 200,000 miles.

The gasoline engine is the part of the hybrid that resembles its traditional counterpart, the gas-powered vehicle. It's just like one you would find on a traditional car, except that it is smaller, thus requiring less fuel to function.

Before hybrids, electric motors were typically used to power smaller devices such as fans, computer equipment and printers. Through what is known as "regenerative braking," braking and accelerating create a steady stream of energy. With the assistance of the car's wheels, the motor functions as a generator, and energy normally wasted from braking and coasting are harnessed.

The top five hybrids ranked by the Environmental Protection Agency in 2008 are, in order of fuel efficiency: Toyota Prius, Honda Civic Hybrid, Nissan Altima Hybrid, Ford Escape Hybrid and the Mazda Tribute Hybrid. Notable hybrid sport utility vehicles (SUVs) and minivans include the Toyota Highlander, Lexus RX 400h, Ford Escape, Mercury Mariner, and the Saturn Vue Green Line. Several hybrids are on the market, and dozens more are being conceived, from the simple to the luxurious and sporty.

While the hybrids are a huge step forward for our nation's fuel economy, they still use gasoline, a finite resource. In addition, the cars do cost significantly more than their gasoline-fueled counterparts. The electric battery in the vehicle adds considerable weight to the hybrids, which lowers a vehicle's fuel efficiency. Plug-in hybrids (PHEVs), which are now in the market, employ an even larger batter pack that drastically reduces the need for gasoline. Extra power can be harnessed by plugging the vehicle into an outlet, hence the name "plug-in" hybrid.