What Is a Hybrid Car? Learn How Hybrid Vehicles Work

Dashboard console display of a hybrid's energy usage module
You have questions about how a hybrid electric vehicle works. We have answers. Peter Dazeley / Getty Images

Have you pulled your car up to the gas pump lately and been shocked by the high price of gasoline? Maybe you've thought about trading in your car for something that gets better mileage — or maybe you're worried that your car is contributing to the greenhouse effect, but you're not ready to go fully electric.

Enter the hybrid car. But how do hybrid electric vehicles work?

What goes on under the hood to give you 20 or 30 more miles per gallon than the standard gas-powered automobile? And does it pollute less just because it gets better gas mileage? Also, where does the plug-in hybrid come in?

In this article, we'll help you understand how this technology works, and we'll even give you some tips on how to drive a hybrid car for maximum efficiency.

Gasoline Power vs. Electric Power

The gasoline-electric hybrid car is just what it sounds like — a cross between a gasoline-powered car and an electric car. Let's start with a few differences between a gasoline-powered car and a typical electric car.

A gas-powered car has a fuel tank supplies gasoline to the internal combustion engine. The engine then turns a transmission, which turns the wheels.

An electric car, on the other hand, has a set of batteries that provides electricity to an electric motor. The motor turns a transmission, and the transmission turns the wheels.

The hybrid is a compromise. It attempts to significantly increase the mileage and reduce the emissions of a gas-powered car while providing the convenience of refueling at the gas station.

Gasoline-electric Hybrid Structure

Gasoline-electric hybrid cars contain the following parts:

  • Gasoline engine: The hybrid car has a gasoline engine much like the one you will find on most cars. However, the engine on a hybrid is smaller and uses advanced technologies to reduce emissions and increase efficiency.

  • Fuel tank: The fuel tank in a hybrid is the energy storage device for the gasoline engine. Gasoline has a much higher energy density than batteries do. For example, it takes about 1,000 pounds (454 kg) of batteries to store as much energy as 1 gallon (3.8 liters) of gasoline.

  • Electric motor: The electric motors on hybrid cars are very sophisticated. Advanced electronics allow it to act as a motor as well as a generator. For example, when it needs to, it can draw energy from the batteries to accelerate the car. But acting as a generator, it can slow the car down and return energy to the batteries.

  • Generator: The generator is similar to an electric motor, but it acts only to produce electrical power. It is used mostly on series hybrids.

  • Batteries: The batteries in a hybrid car are the energy-storage device for the electric motor. Unlike the gasoline in the fuel tank, which can only power the gasoline engine, the electric motor on a hybrid car can put energy into the batteries as well as draw energy from them.

  • Transmission: The transmission on a hybrid car performs the same basic function as the transmission on a conventional car. Some hybrids, like the Honda Insight, have conventional transmissions. Others, like the Toyota Prius, have radically different ones.