Secretary of Transportation Brock Adams recently suggested that the automobile industry develop alternatives to the petroleum-powered engine, apparently not realizing that this goal is akin to asking McDonald's to shift from burgers and fries to oysters a la florentine and beef Wellington.

Impossible? Of course not. But what has to be recognized is that, with odd exceptions, there is an inverse relationship between organizational maturity and technological nimbleness. Thus, the cavalry didn't invent or welcome the tank, the battleship admirals scoffed at the aircraft carrier, the carbon paper trade never dreamed of xerography, instant photography did not come out of the conventional camera industry, and Switzerland's ancient watch industry is yet to recover fully from having initially ignored electronic timekeeping.

In all these instances, and many others, the commonplace problems of looking to the needs of a successful on-going operation tended to squeeze out interest in alternative ways of doing something that was already being done satisfactorily and profitably. It cannot be said that the process is governed by an iron law of technological inertia, for there are exceptions. The pre-World War II radio-manufacturing industry, for example, made a smooth transition to the complexities of television. But, by and large, big, high-technology industries are not searching for technological adventures, regardless of the imaginative tales that their white-coated spokesmen spin during station breaks.

In confirmation of this dour thesis and its durability, it should be noted that Adams, in announcing a new-engine "summit" that's to be held soon, lamented that, "The recent years of trench warfare between government and industry over fuel economy has resulted in a 1978 car that gets about as many miles per gallon as did the Model A 50 years ago." And he said that the government-mandated company average of 27.5 miles per gallon by 1985 should be regarded as a step on the way to a 50-mile average by the end of the century, and then on to non-petroleum propulsion.

Ten days later, the Ford Motor Company called for the government to abandon even the 1985 mileage goals, on the grounds that they "may not be achievable without major disruptions, restrictions of consumer choice and significant price increases." To which Ford added, "What is called for is a complete reassessment of the strategy and aims of the program -- and a scaling-back of its overambitious goals and timetables."

In trench warfare to which Adams referred, that's a standard communique, down to the point of assuming that the proposed reassessment must inevitably point the way to the need for scaling-back.

More candor and less convention were to be found in a talk last week by Paul F. Chenea, vice president in charge of the General Motors Research Laboratories. Speaking on "Innovation, Maturation, and the Automotive Industry," Chenea paid perfunctory court to the wizardries of modern research. But the central point of his talk was, in effect, don't expect too much from this middle-aged, elephantine industry.

"Innovation in the auto industry is usually evolutionary in nature," he said. "Making even incremental innovations in automotive subsystems, which have undergone many generations of major design cycles, requires massive investments in technical manpower and facilities."

And then on to a non-heroic climax on the topic of innovation:

"In most industries, innovation declines as the industry matures. That doesn't seem to be the case in the auto industry. We aren't seeing many 'block busters' like the automatic transmission," Chenea conceded, "but we are seeing a host of incremental innovations which provide a substantial cumulative impact.... The automobile is a mature industry as we are becoming a mature nation. But, to put an old saying in a new context. 'Snow on the roof doesn't necessarily mean there's no fire in the furance.'"

What, if anything, that means is difficult to say. But that sort of thinking isn't going to achieve 50 miles per gallon by the year 2000 -- let alone radically new engines.