It's been clear for a couple of years now that the German luxury makers feel they need competitive responses to the startling emergence of electric-car maker Tesla Motors.

One by one, the concept vehicles--and production plans--have appeared, first the Audi e-Tron Quattro Concept and most recently the Porsche Mission E.

Mercedes-Benz has been more reticent, but now reports of its plans to compete with those vehicles have emerged as well.

DON'T MISS: Mercedes Confirms All-Electric Luxury Car To Fight Tesla 'Very Soon' (Sep 2015)

According to the German magazine Autobild, Mercedes will launch a battery-electric version of its GLC compact crossover utility at the end of 2018, under the model name 'ELC'.

What will presumably be the 2019 Mercedes-Benz ELC electric SUV will share only a roof and windows with the new GLC, which recently launched for the 2016 model year to replace the previous GLK.

The rest of the ELC's body will be heavily modified, to reduce aerodynamic drag to an absolute minimum for longer range.

2016 Mercedes-Benz GLC-Class

2016 Mercedes-Benz GLC-Class

It will have a flat battery pack under the floor, Autobild says, at least two motors (one per axle), up to 400 kilowatts (540 horsepower) of output, and both plug-in and inductive charging.

The ELC's range on the European test cycle is cited as at least 400 km (250 miles), but that's likely to be closer to 200 miles on the U.S. EPA test.

The report suggests that in line with European pricing for the B250e (nee B-Class Electric Drive) versus its diesel counterpart, the ELC's price could be as low as 50,000 euros ($54,000 at current exchange rates).

ALSO SEE: Mercedes: 'More Than Competitive' Electric Cars Possible--When Business Makes Sense

That's because the price is, as the magazine notes, a "political issue"--Mercedes must sell enough battery-electric vehicles to keep it within tightening European Union and U.S. limits on carbon emissions.

Mercedes executive Axel Heix told Green Car Reports two weeks ago that his company was capable of producing "more than competitive" electric cars, when the business case made sense.

He suggested that such cars would be subsidized by more profitable products--the GLS large luxury seven-seat SUV, for instance--but that the company wouldn't build cars that actually lost money.

Audi e-tron quattro concept, 2015 Frankfurt Auto Show

Audi e-tron quattro concept, 2015 Frankfurt Auto Show

While he estimated that profitability could be two or three generations hence, the interview didn't delve into the question of what a luxury-car company has to do to stay in compliance with those carbon-emission and fuel-economy rules.

Between the 100,000 buyers who will soon be driving Tesla Model S cars and those tightening regulations, it may be that the business case makes sense by the end of this decade.

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

German makers generally move in lockstep; when one introduces a new type of vehicle or pioneers a new segment, the rest follow. (Witness the Audi and Mercedes vehicles that mimic the X6 and X4 "sport activity coupes" pioneered by BMW.)

Two different segments seem to be forming for luxury battery-electric vehicles. The first includes the Tesla Model S and, in due course, the Porsche Mission E.

Porsche Mission E concept electric car

Porsche Mission E concept electric car

Then there's the burgeoning SUV or crossover segment, which the Tesla Model X is just pioneering (assuming its delayed production ramp-up proceeds smoothly).

The Model X will be followed in due course by the Audi e-tron quattro (sometimes called the Q6), an electric version of the Jaguar F-Pace, and then the Mercedes ELC.

2013 Mercedes-Benz SLS AMG GT 2-door Coupe SLS AMG GT Grille

2013 Mercedes-Benz SLS AMG GT 2-door Coupe SLS AMG GT Grille

Autobild also suggests that a Mercedes-Benz ELA will follow the ELC.

It would be an all-electric version of the next-generation GLA small crossover, which it says will arrive in Spring 2020, presumably as a 2021 model.

The ELA would be smaller and presumably less expensive than the ELC, and could compete with an SUV version of the planned Tesla Model 3 range of affordable 200-mile electric cars.

2015 Mercedes-Benz GLA 45 AMG, Vermont, Oct 2014

2015 Mercedes-Benz GLA 45 AMG, Vermont, Oct 2014

The company has not commented, as yet, on any plans for a network of DC fast chargers that would enable these pricey electric vehicles to travel long distances.

Audi has pledged that such a network, operating at 150 kilowatts, will accompany its rollout of the production e-tron quattro.

Tesla fans continue to scoff at "concepts" and "plans" and "future cars" from German makers they consider hopelessly behind the curve.

Tesla Supercharger site with photovoltaic solar panels, Rocklin, California, Feb 2015

Tesla Supercharger site with photovoltaic solar panels, Rocklin, California, Feb 2015

But several things will have to go right for the company to maintain its current position in the face of a future German onslaught of luxury electric cars and SUVs.

It promises to be fascinating to watch.

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