Over the next few years, the German luxury establishment--including Audi, BMW, Mercedes-Benz, and Porsche--is expected to launch a barrage of electric car models in a belated attempt to take on startup Tesla Motors.

For some time, it's been understood that one of those models will be an all-electric SUV from Audi.

The carmaker now says that the model will arrive in 2018, as part of a significant expansion of its product lineup.

DON'T MISS: Audi Electric 'SUV Coupe' Arrives In 2018 Or 2019: CEO

During its annual meeting this week, Audi confirmed it will launch a "sporty SUV with electric drive."

This model was discussed at last year's meeting, and was originally thought to be called the Q6 e-tron when it enters production.

Audi CEO Rupert Stadler previously said the vehicle will have a range of 500 kilometers (310 miles), calling that distance a "must."

Audi Q7 e-tron

Audi Q7 e-tron

That figure likely refers to range as measured on the European testing cycle, though. The rated range of the Audi e-tron on the U.S. EPA cycle might come closer to 250 miles.

That would put it just above the base Tesla Model S 70D, which is rated at 240 miles.

Of course, the e-tron's real rival will be the Tesla Model X, which the Silicon Valley company says will launch later this year.

ALSO SEE: How Audi, BMW & Mercedes Plan To Compete With Tesla--And Why (Oct 2014)

Unlike the Model X, however, the Audi e-tron will be adapted from a conventional vehicle platform and offered with gasoline and diesel engines as well as the e-Tron drivetrain. Those conventional versions may arrive before the all-electric model.

It will be distinguished from other utility vehicles in Audi's lineup by coupe-like styling. Audi released a teaser sketch last year showing a vehicle with the tall body of a traditional SUV, but with a low roof line and steeply-angled rear hatch.

Similarly-styled vehicles are already available in the form of the BMW X6 and Mercedes-Benz GLE Coupe, although neither is presently available with a plug-in powertrain.

2016 Audi R8 e-tron

2016 Audi R8 e-tron

Both are essentially restyled versions of existing SUVs, and it's likely that Audi will take a similar route with its electric car.

The e-tron may share at least a platform with another Audi SUV--probably either the next generation of the Q5 mid-size or the recently-launched Q7 large SUV.

MORE: Audi, BMW, Mercedes, Porsche Electric Cars To Target Tesla Model S (Plug-In Hybrids Too) (Dec 2014)

This would follow the template of the Audi R8 e-tron, a version of the second-generation R8 adapted to electric power.

Development of the R8 e-tron was a long and torturous process for Audi, but it may have helped lay the groundwork for the somewhat larger-volume e-tron.

[EDITOR'S NOTE: The Audi e-Tron Quattro Concept, first unveiled at the 2015 Frankfurt Motor Show, was long expected to carry the Q6 designation when it launched as a production vehicle in 2018 or later. In October 2016, however, Audi said the production version would be called simply Audi e-tron. We have updated this article accordingly.]

_______________________________________________

Follow GreenCarReports on Facebook, Twitter, and Google+.