What is a Hybrid Car?

What is a hybrid car? Even with the myriad new coverage and the copious advertising for hybrid vehicles, the fact is that many people are unsure what one really is or how hybrids work. As the name suggests a hybrid car (or any other hybrid vehicle) is one that uses a combination of two power plants to increase fuel economy and reduce emissions.

In the majority of cases hybrid vehicles use a gasoline engine and one or more electric motors. Some manufacturers are developing hybrids that use a small, high efficiency, turbo diesel engine in lieu of the gas engine. Using a turbo diesel as part of the hybrid power train will have advantages in efficiency, emissions, and the ability to use renewable biofuels. The manufacturers developing diesel / electric hybrids are principally European, which makes sense given the popularity of diesel vehicles in Europe. So far Citroen, VW, Opal, and Peugeot have all showed prototype vehicles that have strong production possibilities.

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The hybrid’s electric motors draw their power from a large battery bank in the vehicle. This is recharged either from a generator connected to the gasoline engine, or by a process known as regenerative braking. The regenerative braking is merely recapturing the energy contained in the vehicle because it is moving. Any object that is moving required energy to get it moving at the speed that it’s traveling and maintain that speed. To slow it down, the energy must be removed.

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With a normal vehicle, friction brakes are used for slowing and stopping. These transform the energy contained in the moving vehicle into heat, which is then dissipated into the air. If that seems like a complete waste, it is. The hybrid’s regenerative braking systems actually recapture that energy and store it in the batteries used to power the electric motors for later use. There are one or more generators that are coupled to the wheels under braking. The drag created by the generators when turning the car’s spinning wheels into electricity provide much of the stopping power. This has two benefits; greatly increased brake life, and capturing energy that would have been wasted as heat (and that you already paid for).

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Because internal combustion engines such as gasoline and diesel engines exhibit increased efficiency during different operating conditions, the vehicle can be operated on the optimum power source for a given load condition. At times such as peak acceleration, both power sources can be used in combination. Electric power is typically used when starting out and at low speeds when electric motors are most efficient. The internal combustion engine takes over at higher speeds or when the batteries are discharged.

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There are different types of hybrids. Pure hybrids can move completely on electric power. This can be kind of weird if you’re not expecting it. The first time I experienced this, a Ford Escape hybrid pulled away from a stop as I was standing next to it. It was eerie as the truck silently glided away from the curb, as if by magic. After it was moving about 10 mph, the gas engine kicked in and it motored (engined??) away.

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The stored energy in the batteries let the hybrid’s engine be completely shut down when stopped. The engine is only restarted after the vehicle’s electronic control unit decides it would be better to let the gas engine handle things. More efficiency is gained by using this method. This is similar to the technique used by your internal combustion powered golf cart, but far more sophisticated.

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In fact, the sophistication of engine and control electronics are one of the reasons that practical hybrid vehicles are on the road today. Juggling the optimum mix of power between the two power systems, and recapturing the heretofore lost energy from the moving vehicle would have been impossible to accomplish affordably and practically a few years ago.

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So, that’s what a hybrid car is and kind of how it works. My favorite is the Honda Civic hybrid, followed by the Chevy Tahoe Hybrid, but I’m waiting for someone to make a really cool sports car hybrid, which reportedly Toyota is doing as a replacement for the dear, departed Supra. Toyota probably has more experience than any other manufacturer with hybrids, so they should be well equipped to handle such a task.

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Not to be outdone, Honda is reportedly releasing their CR-Z in about 2011. The CR-Z is a sports coupe in the same vein as the Honda CR-X of 15 years ago, but with a sexy, modern body, great handling, and the hybrid power train from the new Civic hybrid.

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Until next time……..

One Response to “What is a Hybrid Car?”

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