Gas Engines, Mainstay of the 21st Century


The internal combustion engine powered by gasoline will remain the predominant technology for automobiles well into the twenty-first century, three experts in the field agreed at a session during The Industry Summit.

While researchers have developed a variety of alternative engines and fuels, none are competitive with the current system and won't be pressed for until "it looks like petroleum availability will be a problem," said John B. Heywood, director of the Sloan Automotive Laboratory and Sun Jae Professor of Mechanical Engineering.

Dr. Heywood noted that "there's a popular sense that we've made the wrong engine choice-the internal combustion engine is noisy, pollutes the air, etc., etc." But "the reality is that we've made a good choice, and it'll be a good choice-the best choice-for the next 25 to 30 years." (He noted that it's difficult to predict our choices much later than that.)

As an example of why the current system has been-and remains-a good choice, Dr. Heywood said that the emissions characteristics of gasoline as compared with alternative fuels like natural gas, methanol and ethanol are not that different. And "that modest difference is just not worth the negatives of the alternatives and the cost of change." Further, he said, engineers continue to develop petroleum fuels with better and better emissions characteristics.

Nevertheless, there are limits-and tradeoffs-to improvements in petroleum emissions characteristics and in fuel economy for the internal combustion engine, Dr. Heywood said. "If we want a car that gets 50, 80, or 100 mpg we can have it, but it won't be a living room on wheels. It will be much smaller."

Addressing the future, Steven E. Plotkin of the Office of Technology Assessment suggested that automobile manufacturers might want to "leapfrog" over current conventional technology by developing an electric car hybrid. "Unless you make a big leap [by moving to a new system like an electric hybrid], other fuels.can't compete with petroleum," said Dr. Plotkin, who is a senior associate in the Energy and Materials Program of the OTA.

Dr. Plotkin stressed, however, that manufacturers should not introduce such a car too early. "If you take what is potentially a good technology and you move it out too soon, before it is perfected, then you educate the consumer to believe that [it] is a bomb," he said. The electric hybrid is a longer-term solution; Dr. Plotkin wasn't ready to suggest a time schedule for its eventual production.

Any such leap-frog changes should be viewed with humility, however, said John McTague, vice president for technical affairs at the Ford Motor Company. "Almost always such [measures] have seen unexpected consequences."

Moderator Daniel Roos, director of the Center for Technology, Policy and Industrial Development at MIT and Japan Steel Industry Professor of Engineering, concluded the session by remarking that none of the panelists "seemed to argue significantly strongly [for] moving somewhat more quickly" toward alternative technologies. He also said that he found "no sense of great differences [among the panelists] in terms of what our options for the future might be."

Responded Dr. McTague: "We perhaps appear dully uniform because all three of us have spent lots of time looking at the technical data, and after doing so you can only come to the same conclusions."

A version of this
article appeared in the
September 22, 1993

issue of MIT Tech Talk (Volume
38, Number
7).


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