DETROIT — Plug-in hybrid cars, considered exotic, futuristic technology only five years ago, will go further mainstream at this week’s big North American International Auto Show here.

While plug-ins are limited to a few models now, soon they’ll be showing up in dealerships for a wide variety of brands around the country.

Some of the most important new auto models making their debut on Monday and Tuesday here — including Ford’s Fusion sedan, the Chrysler minivan, Volkswagen’s Tiguan GTE crossover concept and Volvo’s flagship sedan — will come in plug-in versions.

The batteries in a typical hybrid get charged from the gas engine. In a plug-in hybrid, the batteries work the same way, but in addition, the car has a cord that can be plugged into an electrical outlet. Drivers can cruise on electricity alone, which vastly increases fuel economy. When the juice runs out, the car relies on its gas-powered engine.

“It’s a gateway drug to full electrification,” says Jake Fisher, director of auto testing for Consumer Reports. “While many people are not ready for a full electric car and all the limitations that go with that, when you have a plug-in hybrid, you don’t have any of those issues.”

Plus, the idea of plugging in a car for pollution-free driving sounds cool.

Examples of plug-ins appearing at the auto show:

•Chrysler. The new Pacifica — a replacement for the Town and Country — is showing Monday as the first plug-in minivan, capable of an estimated 30 miles of electric-only driving before the V-6 engine takes over.

•Ford. The automaker will continue its plug-in version of the Fusion into a new generation being unveiled at the show. Ford says it deserved to be continued. “We have very positive feedback from our customers on the technology, the 19-mile range and overall vehicle,” says Kevin Layden, director of electrified powertrain engineering. Ford CEO Mark Fields announced last month that the automaker is spending $4.5 billion to create 13 hybrid, plug-in or full electric versions by 2020.

•Volvo. The S90 sedan being shown in Detroit will be a plug-in hybrid that has other advanced features, such as being about to drive itself on highways at speeds up to 80 miles per hour, as long as the driver rests a hand on the wheel.

The first popular plug-in was Chevrolet’s Volt, which hit the market in late 2010. Since then, automakers have discovered they can modify hybrids into plug-ins.

At a time of low gas prices, however, their added cost makes them a tough sell with consumers.

Toyota sold 184,794 Prius-branded hybrids last year, but only 4,191 of them were plug-ins, according to Autodata. Chevrolet sold 15,393 Volts, but also sold 184,794 of the similarly sized, plug-less Cruze compacts.

Despite the lower sales, automakers says they’ll need a plug-in portfolio to help them meet tightening government fuel-economy standards.

“We’re looking in the future to satisfy greenhouse gas regulations,” says Volkswagen spokesman Mark Gilles.  “You’ll be seeing more diversified electriciation in our vehicles.”