A Live Green, Live Smart™ Briefing
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The market demand for hybrid cars has exploded over the past few years. More competitive pricing and tax incentives offered at the federal, state and local level have made the gasoline-electric hybrid cars appeal to the mainstream consumer. More than 250,000 hybrids were sold in the US in 2006, a 22 percent increase over 2005 sales. Toyota sold over 12,000 Prius models in February 2007 alone, making it the ninth     best-selling car in the country. In fact Toyota has sold so many Prius models that the manufacturer has begun producing it as a standard inventory item rather than a specialty model. Following the Prius's lead, nearly all foreign and domestic carmakers in the American market have hybrids on the road or in production.

The surge in attention and market share encourages an understanding of the history and inner workings of the hybrid vehicle, and their importance to conversion to energy sustainability and pollution control.

A hybrid car combines a gasoline engine with an electric motor powered by a rechargeable battery. The two components interact, the gasoline starting the vehicle and enabling it to access the battery, or to fall back on fuel when the battery is depleted. This tandem approach increases the efficiency of engine use and increases fuel economy -  often up to 50 or 60 miles per gallon (mpg). A typical hybrid car incorporates a variety of unique features to help it achieve these high mileage numbers:

• Electric-only drive: "Full" hybrids have the ability to drive with only the electric motor running, typically at start-up and low speeds. The gas engine only turns on when high speed, quick acceleration, or battery recharging is needed.
• Power assist: The electric motor assists the engine in acceleration, allowing the gasoline engine to be, in theory, smaller and more fuel efficient.
• Idle-off. When the car is idling - stopped or in neutral - the gasoline engine shuts off. The engine starts again in the time it takes you to move your foot from the brake to gas pedal.
• Regenerative braking. This technology couples with traditional friction brakes to store some of the energy created when braking, which is normally wasted as heat. The electric motor takes over some of the braking duties, storing the energy in a battery for further driving use.

Besides impressive fuel economy, today's hybrids excel at reducing tailpipe emissions of smog-forming pollutants. Most hybrids are nearly zero-emission vehicles (ZEVs), especially the two most popular hybrids, the Prius and Civic Hybrid, which received scores of eight and nine out of 10 on the EPA smog test, respectively. Even the new SUV hybrids score seven or eight on the smog test. Many hybrids (such as the aforementioned Prius and Civic) are PZEVs, Partial Zero Emission Vehicles, cars that are certified by the California Air Resources Board (a body with higher standards than the EPA) to have near-zero emissions.

The first, and still the most popular hybrid is the Toyota Prius, which took to Japanese roads in 1997 and American roads in 2000. The Prius is an expensive and complex car. A computer and "power-splitter" decide, depending on road conditions, speed, and other factors, whether to get power from the gas engine, the electric motor, or both. This system is essentially a combination of two unique systems, and the result is that the engine runs at top efficiency more regularly. The Prius is definitely a gas-sipper, with an EPA-estimated fuel economy of 55 mpg.

Toyota's chief rival, Honda, introduced its own hybrid car in 2000, the Insight, a tiny two-seater. The car's miniature size combined with Honda's hybrid engine give this car exceptional gas mileage: a whopping 63 miles per gallon. Unlike Toyota hybrids, Honda's models feature a smaller gas engine that is assisted by the electric motor. Both run at once, with the motor making up for the energy not produced by the smaller engine. Because of lackluster sales, the Insight was discontinued in 2006.  In 2003 Honda introduced the Civic Hybrid, America's second-most popular hybrid model today. The following year Ford issued the Escape Hybrid, which is distinctive for being both the first American-made hybrid and the first hybrid SUV.

Recently the hybrid market seems to be following the example of the Escape Hybrid rather than the Prius. Although hybrids cars are expected from Nissan, GM, and Hyundai within the next couple of years, the current vogue seems to be for hybrid SUVs, catering to America's love for the bulky profile of these trucks. The result has been a shift in focus from fuel economy to power, using the "hybrid" label without living up to the expectations associated with it.

For example GM is issuing hybrid SUVs - the Tahoe, Yukon, and Escalade - that get a 25 percent increase in fuel economy, thanks to the "two-mode" system introduced for buses. This system brings these SUVs up from a dismal 17 mpg to a meager 21 mpg. An improvement, yes; but green, they are not.

The intent of the "two-mode" system is to allow a smaller gas engine to be coupled with a motor that will handle quick changes in speed. The engine runs smoothly and the motor picks up the extra work. In GM's case, the hybrid systems are attached to engines that are  bigger - more gas-guzzling - than the ones currently used in the SUVs' conventional (and popular) equivalents. It's clear that the hybrid input is not to make a drastic improvement to fuel economy, but to help the huge engine achieve optimal power at any given moment. This makes sense for people who really need a lot of power and towing capacity, but most people who buy these cars do not. Companies produce them and consumers buy them because both parties get substantial tax breaks - the manufacturer gets to claim the benefits of minimal fuel efficiency and smog reduction; the consumer can claim a credit for the hybrid vehicle - and for a "business" vehicle.

GM isn't alone in making these "muscle hybrids:" Dodge, BMW, Mazda, even Honda and Toyota, carmakers that pride themselves on their fuel efficiency, are getting in on the act. The Honda Accord Hybrid has a large V6 engine and has a fuel economy one mpg better than the four-cylinder standard Accord. The result: sales so sluggish Honda is thinking of discontinuing the model.

The rise of the muscle hybrid helps spotlight the original intent of the hybrid. Because the atmosphere is filling up with greenhouse gases and the ground is emptying of fossil fuels, it is absolutely essential that we begin to make and drive cars that get excellent fuel economy. Doing this will have the single greatest effect on America's oil dependence and wasteful ways. Fifty percent of America's auto sales are light trucks - pickups, SUVs, and minivans. As the years have gone by America in general has become less fuel-conscious, not more. 

Early models of hybrid cars are steps forward - fundamental shifts in the way America drives. The modestly efficient hybrid SUV is an irresponsible and costly step backward. As demonstrated by those who have done hybrids right, the technology and the ingenuity are available to dramatically improve fuel economy in America and around the world. Yet carmakers still choose to shirk these imperatives to build bigger, hungrier cars and trucks. If carmakers choose to use the "hybrid" label, they should live up to the spirit as well as the letter of the designation.

The Prius's status as the ninth-best selling car in America is evidence that many people are not only willing to pay the price for better fuel economy, they have the desire to do so. With luck - and a clean environmental conscience - their ranks will continue to grow.

Written for Live Green, Live Smart by Jack Hays (jack@jacksonhays.com)