Toyota Chairman Eiji Toyoda, left, and General Motors Chairman Roger B. Smith shake hands in front of a Chevrolet Nova at the United Motor Manufacturing plant in Fremont, Calif., that was Toyota’s first step into manufacturing outside Japan. (Paul Sakuma/AP)

Eiji Toyoda, who spearheaded Toyota Motor Corp.’s expansion in the United States as the automaker’s longest-serving president, died Sept. 17 in Toyota City, Japan. He was 100.

Toyota Motor announced the death and said the cause was a heart ailment.

Mr. Toyoda helped reshape a maker of Chevrolet knockoffs into an automaker whose manufacturing efficiency became the envy of General Motors and Ford Motor Co. By the time Mr. Toyoda stepped down in 1994, the company was assembling Corollas in the United States, had started the Lexus luxury brand and had initiated a project that would develop the world’s most successful gas-electric hybrid, the Prius.

Toyoda was a younger cousin of Kiichiro Toyoda, the founder of the company that bears a slightly altered version of the family’s name. He was one of six company presidents to come from the family.

During the 69 years he worked at the company, based in central Japan’s Toyota City, it rose from assembling its cars out of parts made by GM to being 16 times more valuable than the Detroit-based automaker. Eiji Toyoda pushed his company to learn from Ford and GM about mass production of automobiles.

Mr. Toyoda became president of Toyota Motor Co. in 1967 and served for 15 years — longer than anyone before or since. In 1982, Toyota Motor and Toyota Motor Sales Co. merged to form Toyota Motor Corp. Mr. Toyoda became chairman of the combined company and served until 1992. He was made honorary chairman of the company upon retirement and kept the title of honorary adviser.

Under his stewardship, the carmaker set up at least 10 new factories, began exporting to dozens of countries and built a reputation for manufacturing excellence.

The Corolla, introduced in 1966, became the best-selling car of all time. Mr. Toyoda stressed the importance of manufacturing concepts that became central to Toyota’s production methods, such as “kaizen,” or continuous improvement, and “jidoka,” the use of machines that shut down when irregularities are detected.

His greatest achievement may have been laying the foundation for the company to apply its manufacturing expertise overseas, which led to the formation of Toyota’s first venture in the United States in 1983 — a year after Mr. Toyoda passed the presidency to his cousin, Shoichiro.

That venture, New United Motor Manufacturing, in partnership with GM, began production in 1984 in Fremont, Calif. Its success showed that Toyota’s manufacturing principles could be applied across cultures, giving the company the confidence to make its own independent plants in Kentucky, Canada, England and France, according to Mr. Toyoda.

He also oversaw Toyota’s development of the Lexus, approving development of the luxury car in 1983 to compete with Mercedes-Benz and BMW. The first vehicle, the LS 400, went on sale in the United States in 1989.

The U.S. Automotive Hall of Fame inducted Mr. Toyoda in 1994, making him the second honoree from Japan, after Soichiro Honda.

Eiji Toyoda was born Sept. 12, 1913, near Nagoya in central Japan. He grew up inside his father’s textile mill, schooled from an early age in machines and business, according to his autobiography, “Toyota: Fifty Years in Motion.”

Mr. Toyoda graduated from the University of Tokyo with a degree in mechanical engineering in 1936 and joined Toyoda Automatic Loom Works Ltd., working for his uncle, Sakichi Toyoda, inventor of a loom that automatically shut itself off when a piece of fabric broke.

At the time, Sakichi’s son, Kiichiro, was heading an automobile division of Toyoda Automatic Loom Works. In 1937, Kiichiro founded Toyota Motor and took his younger cousin with him.

Eiji Toyoda, then in his 20s, started on the factory floor before being promoted to production planning and director. From the outset, he was given broad freedom to pursue interests ranging from fixing cars to helping establish the company headquarters in Toyota City. He became a director in 1945.

Toyota and Ford held discussions on jointly making cars in the United States, but they were cut off after the Japanese attack on Pearl Harbor in 1941. Talks resumed after World War II but did not lead anywhere.

In 1950, during its occupation of Japan, the U.S. Army sent Mr. Toyoda to Dearborn, Mich., to learn about mass production from Ford. The United States wanted Toyota to build trucks for its troops in Korea.

“We were producing 40 cars a day,” he later recalled. “Ford was making 8,000 units, a 200-times difference.”

But Mr. Toyoda concluded that Ford was barely ahead of the much-smaller Toyota in terms of technology. Back in Japan, he concentrated on making cars in small batches at maximum efficiency. He began using IBM machines to cut production costs, according to Kazuo Wada, professor of economics at the University of Tokyo and author of “A Fable on Manufacturing: Ford to Toyota.”

Building on the work of his cousin, Mr. Toyoda developed what became known as the Toyota Production System, which aimed to eliminate excess inventory of parts and other waste. The manufacturing system became so successful it was eventually adopted by other carmakers and by manufacturers outside the automotive industry.

He had four children with his wife, the former Kazuko Takahashi. Survivors include his eldest son, Kanshiro, according to Toyota.

Bloomberg News

Washington Post staff writer Adam Bernstein and Laurence Arnold and Masatsugu Horie, both of Bloomberg News, contributed to this report.