We already know that in the next few years, we'll see a slew of mid-size SUVs offered with plug-in hybrid powertrains--most from luxury brands like Audi, BMW, Mercedes, Porsche, and Range Rover.

But the German luxury marques are making plans to compete more directly with Tesla Motors and its Model S all-electric long-range luxury sedan.

All have current or upcoming luxury plug-in hybrid models--but only BMW offers one battery-electric vehicle, and it's the i3 city car. (Mercedes-Benz also has the low-volume B-Class Electric Drive, on sale in limited areas of the U.S.)

DON'T MISS: Audi Startled By Tesla Sales Success? Deleted Press Release Seems To Say So (May 2013)

According to various news reports, several of those luxury brands plan to offer all-electric sedans before the end of the decade that would essentially line up against the Tesla Model S or an updated version of the car.

For instance, Germany's Manager Magazin (via Motor Authority) cited industry sources saying that the upcoming smaller Porsche sedan (now known as "Pajun," for Panamera Junior) will include an all-electric version.

2014 Porsche Panamera S E-Hybrid

The magazine says the Pajun will be built on a second-generation version of the VW Group's larger modular architecture, known as MSB.

The electric version, it says, should go on sale in 2018 or 2019, and offer power comparable to today's Model S.

Audi, Mercedes too

And that's not all. The Volkswagen Group's luxury brand, Audi, is said to be planning an all-electric version of its upcoming Q8 "four-door coupe utility vehicle."

ALSO SEE: Targeting Tesla Model X: 2017 Audi Q8 e-tron All-Electric Crossover Utility

To be launched at the end of 2017 or later, the Q8 e-tron would have the upcoming Tesla Model X electric SUV squarely in its sights.

BMW is thought to be working on larger, more upmarket all-electric vehicles based on its i3 architecture. And, finally, Mercedes-Benz is said to be considering an all-electric version of its S-Class large luxury sedan.

All of those vehicles except the BMW would presumably use largely steel construction, which would make them considerably heavier than the all-aluminum Model S.

2016 Audi A3 e-tron plug-in hybrid

They would also be adaptations of platforms designed first for gasoline and diesel power, which are inherently not optimized for electric power as the Tesla is.

Manager claims that the all-electric Pajun will be lighter than the Model S; we'll wait to see how they stack up in three or four years.

Our unpublished anecdote

The push by German brands to build all-electric sedans is supported by a story we've never before published.

It came from a longtime insider in the incestuous German auto industry, a man with many colleagues at multiple makers.

2016 Mercedes-Benz S550 Plug-In Hybrid

He told us the story on condition that we not source it to him, or identify the specific maker.

But it illustrates why we may soon see a slew of all-electric sedans from German luxury makers that you might call Tesla-alikes.

Finally, a Model S to evaluate

Almost two years ago, early in 2013, one of the German prestige brands finally got its hands on a Tesla Model S and took the car to its test track and tear-down facility.

2014 BMW i3 4-door HB Grille

The company's drivers hammered it around the track, recharged it, and drove it more.

Then the company's product board were asked to come to the test track and do the same.

Altogether, the Tesla spent several days being driven at low and high speeds, and everything in between. We gather it performed flawlessly.

Emergency meeting

Then the executives responsible for future products convened a meeting.

2016 Mercedes-Benz S550 Plug-In Hybrid, U.S. pre-production car tested, Stuttgart, Germany, Aug 2014

They concluded that the Model S electric luxury sedan--a good-looking all-aluminum vehicle from a carmaker that didn't exist 10 years ago--provided a fast, comfortable, technologically advanced driving experience.

An experience, moreover, that nothing in their current lineup--and nothing that this carmaker even had on the drawing board--could match.

And that was deeply, profoundly unsettling to this particular maker, whose cars are world-renowned for their brand image.

Tesla Model S tackles the Nurburgring

Fast forward perhaps six or seven years, and that deficiency may have been remedied.

The question, of course, will be whether Tesla is a moving target--and whether these German electric sedans are targeting a car that's already about to be replaced.

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