General Motors has confirmed what we already told you: It will build a Cadillac plug-in hybrid using the Chevrolet Volt’s drivetrain, a move that further underscores its commitment to cars with cords.

The General announced today that the Cadillac Converj concept has been approved for production, although in keeping with Caddy’s alphabet-soup naming it will be called the ELR.

“The concept generated instant enthusiasm,” Don Butler, VP of Cadillac marketing, said in a statement. “Like other milestone Cadillac models of the past, the ELR will offer something not otherwise present -– the combination of electric propulsion with striking design and the fun of luxury coupe driving.”

There aren’t a whole lot of details at this point — the price, performance specs and exact timing are anyone’s guess — but earlier reports say we’ll see the car by the end of 2013. Based upon GM’s vague description of the drivetrain, we’re looking at a sexier Chevrolet Volt, with more oomph.

For the few who may not know, the Chevrolet Volt is a plug-in hybrid, certified by the Environmental Protection Agency with an electric range of 35 miles. As the 16-kilowatt-hour battery winds down, a 1.4-liter gasoline engine drives a 53-kilowatt generator (and, in some rare instances at high speed, helps the electric motor turn the wheels) to keep juice flowing to the 111-kilowatt motor. We’ve spent a lot of time driving the Volt and can tell you it’s an impressive car that’s smooth and comfortable with decent performance.

The Converj was a hit of the 2010 2009 Detroit auto show, and there have been recurring reports — neither confirmed nor denied by GM — that the car would see production. The most recent came last week when John Voelcker of Green Car Reports, citing an unnamed source, said the car had been approved for 2013 as a 2014 model.

Voelcker’s source, said to be “close to the project,” said the car will feature “a Generation 1.5 Voltec drivetrain” with a little more performance than the Volt. That’s important, because among the concerns GM brass reportedly have had in the past was the Voltec system wouldn’t provide the performance people expect from a Cadillac. It’s almost certain that we won’t see a repeat of the Cadillac Cimarron fiasco, but General Motors will have to ensure that the ELR delivers the driving experience people expect.

That shouldn’t be a problem, said Aaron Bragman, an industry analyst with IHS Automotive.

“The biggest complaint people have with the Volt is not how it drives,” he said, “but how much it costs.”

The Volt is indeed pricey — the model we tested came in at $44,680 before the federal EV tax credit — because the underlying technology, namely the 16-kilowatt-hour battery, is expensive. Rolling out the Voltec drivetrain in a Cadillac won’t do much to change that, because it won’t increase volume enough to bring economy of scale, Bragman said, but it will make it easier for consumers to accept the price.

That’s why you see luxury brands like BMW, Lexus and Mercedes-Benz rolling out upscale hybrid sedans.

“That cost is more easily masked in a car like this,” he said. “GM can better accommodate the price without the sticker shock. You expect a Cadillac to cost a lot. You don’t expect a Chevrolet to cost a lot.”

That said, the decision to introduce a plug-in Cadillac underscores General Motors’ commitment to the technology.

“This is just the tip of the iceberg,” Bragman said. “We’re going to see this in a lot more vehicles.”

Next up? Perhaps the Chevrolet MPV5 concept we saw in Beijing last year …

Photo: General Motors