Hybrid tech

Comparing the design, engineering and systems of the cars that we pioneering the 21st century automobile.

As brand-new vehicles go, Hondas Insight and Toyota's Prius won't be busting any U.S. sales charts soon. Most buyers shopping for 2000-model vehicles won't even be aware of the hybrid-electric cars, much less seriously consider them. High fuel economy and superclean exhaust emissions are just not what, the American public wants in its cars and trucks - at least not today.

However, the auto industry's radar screen has far greater scope than the public's, and that's why other automakers and suppliers are keenly interested in Insight and Prius. As the world's first hybrid production cars, they're powered by a combination of gasoline-fueled internal combustion (IC) engines and electric motors. They don't have the limited range and charging hassles that plague pure EVs. You can tank them up at any gas station. And they'll return stunning mileage. In fact, Insight recently became the EPAs fuel economy king, with a rating of 70 mpg highway, 60 city. (See Cars Worth Noting, p. 14).

Such performance comes from the cars' pioneering technologies. Electric drive systems, sophisticated power controllers and software, and lightweight structures are "the building blocks of mass-produced future vehicles," says Mike Robinet an industry analyst with CSM Worldwide in NorthviIle, Mich He predicts that today's hybrid drives will prove-out the technology preparing it for fuel cells later on.

For now, however, Honda and Toyota are the Neil Amistrongs of the auto industry. They got there first. That pays dividends with federal and state legislators and regulators, to whom Honda showed the Insight after its media debut in Washington, D.C., last September. Automakers hope that hybrids will help convince government that the industry can create better environmental solutions. Hybrids may also help automakers get partial credit for meeting the 2004 California zero-enussions laws.

Worldwide, however, fuel economy and emissions issues are pressing concerns. "Hybridization allows you to unprove both of those things, while having room for passengers and packages, makes the car practical and useable," explains DaveHermance, executive engineer, environmental engineering at Toyota's U.S. technical center.

Toyota got the jump on Honda in launching its hybrid, but it will not beat Honda to the U.S. because of poor forward planning. The Prius, which went on sale in Japan in December 1997, and has since sold neariy 30,000 units, was not originally designed for left-hand steer. When engineers tried to modify it late in 1997, they realized they would need to redesign the power electronics to accommodate the steering column. The U.S.-spec Prius that debuts at the Detroit auto show next month will have this change and other upgrades, including revised styling. It will differ from the Japan-market car we used for this story. Toyota hopes to sell 12,000 in the U.S. next year.

While Toyota went for sedan practicality, Honda aimed for pure economy with the Insight, notes Chief Engineer Koichi Rikuo. Thus a slick (0.25 Cd) coupe that's priced under $20,000 and aiming for about 10,000 sales worldwide (4,000 in the US.) next year. Fresh out of the blocks, here's how Insight compares with Prius.

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Honda Insight

Slippery coups body is less practical than Prius, but for more aerodynamic

Tapered rear end has Kamm-type tail, rear track that's 4.3 in. narrower than front to reduce turbulence

Skirted rear wheelhouses,underbody pans help achieve 0.25 Cd

1,856-lb. curb weight is 077-lb. lighter than Prius, 503-lb. lighter than bass Civic hatchback

Body structure is aluminum with nylon-reinforced ABS plastic front fenders and rear skirts

Chassis is 160-lb. lighter than Civic's. Strut-type front suspension has aluminum lower arms, knuckles, be rod, brake calipers

Electric rack-andpinion steering adopted from NSX saves power

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Toyota Prius

Curb weight is 2,733 pounds about 250 pounds heavier than a Corolla, and 330 pounds more then a Ford Focus sedan.

At 1683 inches overall length, Prius is slightly shorter than a Focus.

Five-passenger layout gives far better utility than Insight

Body is in high-tensile steel, generously reinforced for rigidity.

Underbody airflow is carefully managed using covers under engine and rear floor, air dams ahead of front tires and flat-bottom fuel tank.

To boost A/C efficiency, special coating on side glass and rear window reduces solar load by 13%. Foam panels in roof also keep out heat

Ducktail on body's trailing edge also helps achieve drag coefficient of 0.30 Cd.