AUTOS: Diesel Dazzle

The New York City cabby was beaming. "It costs me about a third less to run this thing," he said. "I've already saved two hundred bucks."

His moneysaving (and -making) chariot is a Peugeot 504, powered by a diesel engine. At a list price of $8,260, the French-made Peugeot does not exactly qualify as low-priced. But the obvious economy of driving diesels is attracting more and more U.S. motorists: while diesel fuel costs about the same as gasoline, diesel engines get up to double the mileage. From 1974 to 1975, sales of diesel cars...