Techsplanations: Gas-Electric Hybrid

What is it?

A hybrid is a car or truck that has both an internal-combustion gasoline engine and an electric motor to drive its wheels. These two work together to power the car in the most efficient fashion possible. This means that sometimes the gas engine drives the wheels alone, while other times the electric motor adds its power. Some hybrids even allow the electric motor to power the car for limited distances all by itself.

There are several different kinds of hybrid systems, including hybrids that you can plug in to recharge their batteries. We're going to save discussion of those plug-in hybrids for a separate Techsplanation, and focus on regular hybrids that don't have a cord.

How does it work?

Gas-Electric Hybrids work just like regular cars. You put gasoline in them, and you drive them around, and when their tanks hit E, you head back to the gas station. Except that hybrids have some additional equipment, starting with their electric motors.

Hybrids have at least one electric motor and often two. These are usually mounted somewhere in the transmission or between the engine and transmission, so that they can add their power output to that of the gas engine. The electric power for the motor comes from the battery pack, which is often mounted under or behind the rear seats. Hybrids also have regenerative braking systems, which work by spinning the electric motor backwards during deceleration. This turns the motor into a generator, producing electricity that recharges the battery pack.

All of this is managed by a sophisticated computer system that determines when it's best to use the electric power. The computer will also decide when it's okay to shut down the gasoline engine to conserve fuel, like when the car is stopped at a light. Hybrids can restart their gas engines instantly because they use their electric motors as starters. Most hybrids also feature prominent graphical displays to show in real time where the energy to power the wheels is coming from.

Why would I want it?

One reason: Improved fuel economy. Hybrids are among the most fuel-efficient vehicles on the road, with the Toyota Prius topping them all by hitting 50 miles per gallon combined. And this improved fuel economy also decreases emissions, making hybrids better for the environment.

While some manufacturers have used hybrid technology to boost performance, most hybrids have been designed with fuel economy as the primary consideration.

Is there any downside?

Hybrids have a lot of additional equipment that's not found on conventional vehicles. This adds weight, complexity and cost, though manufacturers have done a good job compensating for all three factors. Still, you'll generally pay more for a hybrid than you would for a similar sized non-hybrid vehicle, and while it will usually offer better fuel economy, it may not perform quite as well in acceleration or handling.

What vehicles offer it?

Though Toyota and Honda were the hybrid pioneers, most manufacturers are offering a hybrid of some sort these days, or at least have one planned. Dedicated hybrid models include the Toyota Prius and Honda Insight. Many midsize sedans are available in hybrid versions, like the Toyota Camry Hybrid, the Ford Fusion Hybrid, the Hyundai Sonata Hybrid, and the Kia Optima Hybrid. Several hybrid SUV's have become popular over the past few years, including Ford's Escape and Toyota's Highlander, while the Lexus RX 450h is been the best-selling luxury hybrid. Hybrids are currently available from Buick, Cadillac, Ford, Honda, Infiniti, Kia, Lexus, Lincoln, Porsche, Toyota, and Volkswagen. BMW and Mercedes-Benz have announced hybrids that will come to market this year.

Bottom line

Hybrids are the best solution the auto industry has yet come up with for improving fuel economy without giving up the convenience of gasoline refueling.

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