Infographic: How Does a Hybrid Car Engine Actually Work?

Rated by the Environmental Protection Agency (EPA) at 51 mpg in the city and 48 mpg on the highway, the Toyota Prius has long been one of the most popular hybrid cars in the United States. We know about hybrid cars and their impressive sales over the past several years, but how do they actually work? Just what is it inside of that car that allows it to get much better mileage -- something we all want, especially in the summer when gas prices, it seems, are always climbing -- than traditional vehicles?

AutoMD has put together the infographic embedded below in an attempt to help shed a little light on how hybrid engines function. Focusing on the third generation of the Toyota Prius, which debuted in 2010, AutoMD covers the various components and explains how they all work together.

Infographics are always a bit of a hodgepodge of statistics culled from a variety of sources. Here, we sort through the clutter and pull out some of our favorite facts and figures:

  • The price of gas is a major reason why sales of green cars, including hybrids, are expected to increase four times by 2016.
  • Seventy-five percent of those who say they would consider a hybrid car cite lower fuel costs as the main reason.
  • The Toyota Prius, the world's most popular hybrid car, uses a combination of an internal combustion engine and a battery electric drive system to increase fuel economy and reduce emissions.
  • When pulling away from a stop, the electric motor powers the car, drawing on the battery for power. Up to 15 mph, the vehicle uses only the electrical motor for power. This is one of the reasons why hybrids are more efficient during city driving than on the highway.
  • During normal cruising only the gasoline engine is used because this is when it is most efficient. During cruising, the gasoline engine can also power the generator, which produces electricity and stores it in the batteries for later use.
  • During heavy acceleration both the gasoline engine and the electric motor work together to increase power to the wheels. The joint effort of the engine and motor working together is only possible because of the power-split transmission, which combines the torque that each one puts out. At this time, the gasoline engine also powers the generator. The electric motor uses electricity from the battery and the generator as needed.
  • The Prius reaches 51 mpg in the city and 48 mpg on the highway.
  • The Toyota Prius emits 71 percent less CO2 than a Hummer H3, and 20 percent less methane gas than an adult sheep.
  • The Volkswagen diesel L1 concept car is due to hit the market in 2013 and will be the most fuel-efficient hybrid. The L1 could make it from New York City to Los Angeles on just 11.8 gallons of fuel. It can travel 100 km on a single liter of fuel, which translates to 235 mpg.

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