We’re changing. Transition is in ample evidence here at the 64th iteration of the Frankfurt Auto Show, which opened to the public Thursday and runs through next Sunday. It is the world’s largest biennial display of all things automobile.

The change is as obvious as a collection of horseless carriages presented to the public at Germany’s first automobile show, held in 1897 at the Hotel Bristol in Berlin.

And the change is as subtle as side-parlor conversations with international executives of the world’s biggest oil companies. Hint: They no longer refer to their corporations as “oil companies.” Nowadays, they much prefer the term “the energy business.”

It matters not whether future automobiles run on gasoline, diesel, lithium polymer batteries or some other form of electric power, liquid propane, or natural gas — the companies now known as Exxon Mobil, Shell and BP want to provide the fuel.

Theirs is not environmental homage. It is a quest for future profits. If the oil runs out, they must get money from selling something else.

Change is everywhere among the estimated 900 automotive and supplier pavilions here, which represent more than 30 countries. The displays are massive, and super-expensive. Several exhibits, by German automotive powers BMW, Mercedes-Benz and Volkswagen, occupy entire buildings.

You literally can walk back and forth eight miles, all day long, which I and a colleague did on the opening media day, and not see everything . . . or even close to it.

But some sample views are instructive.

There is BMW, maker of the “ultimate driving machine,” long an apostate in matters of electrically driven vehicles, showing off its “i”-class concept cars.

The BMW display says “i” means “born electric.” There is the i3 urban concept car and the i8 luxury-sports concept. Both are sleek, snazzy all-electric cars powered by lithium-ion batteries. Both employ high-strength, lightweight composite materials to help shed vehicle-body pounds without undermining safety and reliability. Both, BMW officials contend, are more than concepts — meaning they are automotive studies with some realistic possibilities of production and retail.

This is more than fanciful murmuring.

Market-ready all-electrics and hybrid-electrics are on display at every major automotive pavilion. There’s the all-electric Volvo C30 and Ford Focus. There’s the plug-in hybrid Chevrolet Volt and Opel Ampera. There are all manner of fossil-fuel hybrids from Toyota, BMW, General Motors Europe, Mercedes-Benz and Ford of Europe, among many others.

Electrics clearly are here to stay as both local commuters and long-range drivers. But no automotive executive here believes that electrics will dominate the retail market anytime soon.

The future, near- and long-term, will be powered by petroleum. That is the consensus. In Europe, that means diesel — clean, relatively quiet advanced diesel engines — engines at least 30 percent more fuel-efficient than their gasoline counterparts. For the United States, however, that mostly means advanced-technology gasoline engines, or gasoline-electric hybrids, or plug-in electric, gasoline-assisted, extended-range hybrid vehicles.

Talk to the executives of U.S.-based automobile companies here and you get two different stories on diesel possibilities for the diesel-resistant American market.

Ford, which has invested heavily in advanced, fuel-efficient four-cylinder EcoBoost gasoline engines, says it has no near-term plans to bring diesel-powered vehicles to the United States. “We can’t make a business case for nit,” said one U.S. Ford executive, speaking on background. “Diesel fuel is too expensive in the United States. And the regulatory climate for diesel at home make it a non-starter.”

But over at GM’s Chevrolet division, officials are promising to bring diesel-powered compact Chevrolet Cruze sedans to the United States for the 2013 model year.

There is a kind of product schizophrenia here, also evident at other international shows. The industry has invested in — and is continuing to put billions of dollars into — alternative fuels and alternative propulsion systems. Yet it is reluctant to move entirely away from muscle.

There is a new, slick, fuel-efficient Honda Civic. There is a huge, beautifully over-the-top Cadillac Ciel concept luxury convertible. It is not the least bit difficult to find excess horsepower here.

Change happens, but it does so slowly. No one wants to get too far ahead of the market. No one wants to fall too far behind. I’ll return to product reviews next week.