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TOKYO -- Toyota Motor Corp. has quietly introduced a new engine in the U.S. that requires nearly 25% fewer parts to build than its predecessor, substantially cutting both weight and cost.
The No. 1 Japanese auto maker made the new engine standard equipment on the 1998 U.S. version of its compact Corolla introduced this fall. While Toyota's work on a lighter and cheaper engine was known previously, the engine 's first use in the new Corolla went little noticed.
The development helps to explain how Toyota was able to cut the price of the new Corolla in the U.S. by 10%, or more than $1,000, from that of the model it replaced. Toyota already ranks as the world's most efficient auto maker, making its further cost-cutting moves closely watched by rivals from Detroit to Stuttgart, Germany.
A year ago, Toyota finance executive Ryuji Araki disclosed that Toyota was developing a "simple and powerful" engine that would use a third fewer parts. As rivals began speculating about how the company could produce such an engine , the normally tight-lipped Toyota resumed that stance, with some Toyota officials even dismissing Mr. Araki's comments as uninformed. In addition, the engine wasn't introduced in Japan, as had once been expected.
Now Toyota acknowledges that the redesigned, 1.8-liter, dual overhead cam, all-aluminum, four-cylinder engine in the new Corolla contains just 560 parts, nearly 25% fewer than the previous engine's 741. The engine weighs 64 pounds, or about 10%, less than its predecessor and generates 120 horsepower, a 15% increase, making the new Corolla much peppier.
The new engine also offers a 10% gain in fuel economy and a substantial reduction in emissions. And the compact configuration of the new engine allowed designers to give the new Corolla a shape that has about the same low wind resistance as a Toyota Supra sports car.
"We do believe that the Corolla engine deserves special attention," a Toyota spokesman in the U.S. said yesterday. He said that in press previews last summer the company described the advances represented by the engine , but "we didn't focus attention on it" because marketers also wanted to promote the redesigned car's advances in crash-worthiness and other safety elements.
Still, top officials at Toyota's headquarters remain low key about the new engine. Akihiro Wada, Toyota's executive vice president in charge of research and development, described the engine as evolutionary, not revolutionary. He pointed out that some material costs increased on the engine, since more aluminum was used to cut weight.
Still, independent industry experts are impressed. "It's a monument to value-engineering capability," said James Womack, president of the Lean Enterprise Institute, a nonprofit educational organization. David Cole, director of the University of Michigan's Center for the Study of Automotive Transportation, said: "It's a pretty substantial reduction in costs."
Industry experts estimate that a conventional four-cylinder engine costs an auto maker $600 to $700, so a 25% cost reduction might amount to more than $150 a car -- a huge amount in an industry that shaves costs by nickels and dimes.
Toyota engineers flipped the intake runners to the front of the engine, eliminating several secondary brackets, says Suguya Fukusato, the chief engineer on the Corolla. Positioning the exhaust manifold at the rear of the engine, instead of in front, shortened the exhaust train and helped cut emissions, a spokesman says. Engineers made the water pump part of the engine block.
Increased combustion efficiency lowered water temperatures, allowing for a radiator core that is 41% narrower than before. The engine requires just one catalytic converter, unlike many competing engines that require two.
Toyota developed three distinct Corolla models to cater to North American, Japanese and European tastes. Mr. Fukusato said the new engine being installed in North America differs from those being sold elsewhere partly because, in Europe at least, the market demands an even smaller engine. In addition, he said, the special additional pollution-control equipment necessary to meet low U.S. emissions standards make the engine too expensive to offer in Japan or Europe, where emissions regulations are less stringent.