OKAZAKI, Japan — Speculation that Mitsubishi Motor Corp. may de-emphasize its hallmark gasoline direct injection (GDI) engine is premature.

To the contrary, in fact, as the automaker late last month promoted its two top GDI engineers.

Akira Kijima, chief proponent of the company's trademark GDI engine, now is senior executive officer and corporate general manager for research and development at Mitsubishi's newly reformed Passenger Car Research & Development/Marketing Headquarters in Okazaki.

Meanwhile, Hiromitsu Ando, Mr. Kijima's collaborator on the GDI program, is executive officer and project leader overseeing powertrain development at the Okazaki headquarters.

Mr. Ando, who joined Mitsubishi mid-career after working several years at Tokyo University as a research chemist, insists that the GDI engine is alive and well — though he concedes that future developments will be more market-driven than in the past.

Still, at this year's Society of Automotive Engineers Congress & Exposition in Detroit, the automaker presented four technical papers involving the GDI and announced development of a new oxides of nitrogen (NOx)-absorbing catalyst for use at high engine temperatures common during extended high-speed driving, such as in Europe.

Specifically, improvements in the catalyst carrier, washcoat and K-retention layer minimize the effects of gasoline-sulfur poisoning. Mr. Ando reports that Mitsubishi's newest catalyst can desorb gasoline sulfur in concentrations slightly less than 50 parts per million (ppm), and thus can easily meet the 2011 target of 10 ppm set by the European Union for the petroleum industry.

“But this will cost more,” he warns. “Our existing GDI system has a $300 penalty. To meet future emission regulations, this penalty will increase to $400,” mainly the result of increased usage of ancillary catalytic materials such as zeolite, silica and titanium.

Even at the current cost, Mitsubishi produced and sold more than 195,000 GDI vehicles last year, including 167,360 in Japan, almost 60% of company domestic sales.

With respect to Mitsubishi's relations with DaimlerChrysler AG, Mr. Ando confirms that the company currently is reviewing engine and transmission families with the intent of reducing the overall number.

Analysts predict the company will shrink its engine lineup to five or six series, from eight today. These will include one 3-cyl. engine, three I-4s, one V-6 and one V-8.

In all likelihood, Mitsubishi will turn to Chrysler for the V-6 and V-8.