Future Doubtful for Wankel Engine at Mazda

Mazda Motor Corp. tells Automotive News it won't resume production of its fabled rotary engine unless it can use the system in a vehicle that generates at least 100,000 sales per year.

CEO Masamichi Kogai says any lesser volume would not be profitable.

Kogai, who took over as CEO in June, helped Mazda to its first profit in five years in the fiscal year ended March 31, in part by overhauling the company's Japanese factory operations in his previous role as manufacturing boss.

In 1968 Mazda became the first mass-market producer to offer a rotary engine. Its best year came in 1986 when the company sold 56,000 RX-7 sports cars in the U.S., its strongest market. By 2011 demand there had dropped to fewer 800 units. The engine was killed when RX-8 production ended last year.

Though the engine faces problems meeting increasingly stringent emissions limits, the rotary may make a comeback as a compact power source for onboard generators used in extended-range electric vehicles. Its chief value is the engine's ability to run on a variety of fuels, including hydrogen and kerosene.