It's now clear that we'll see a slew of all-electric luxury vehicles with ranges of 200 miles or more from German makers Audi, BMW, and Mercedes-Benz starting in 2017 or 2018.

What's less clear is whether those vehicles will be developed as electric cars from the ground up or whether they'll be adapted versions of gasoline models.

The current BMW i3 electric car has no gasoline-only counterpart, for example, so it's an example of the former--but the Volkswagen e-Golf is all but indistinguishable from gasoline and diesel Golfs.

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One of those German luxury electric cars seems likely to share much of its understructure, if not its body shell, with gasoline models.

According to Britain's Auto Express, the upcoming Audi e-tron electric "SUV coupe" will be "sexy and sporty"--and arrive in 2018 or 2019.

Audi Q7 e-tron

Audi Q7 e-tron

Audi confirmed production of the electric car at its annual meeting last month, releasing a teaser sketch that indeed showed a low, sleek coupe-like hatchback with large wheels.

Then Audi CEO Rupert Stadler told Auto Express at the Shanghai Auto Show that the car would have at least 500 km (310 miles) of range, calling that distance "a must."

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Stadler was likely quoting range numbers from the European test cycle, so the rated range of the Audi e-tron on the U.S. EPA cycle might come in at more like 250 miles.

Still, that's within range of the Tesla Model S, whose most recent entry-level 70D model is rated at 240 miles.

2015 Tesla Model S 70D, Apr 2015 [photo: David Noland]

2015 Tesla Model S 70D, Apr 2015 [photo: David Noland]

Stadler also suggested that the e-tron would arrive in 2018 or 2019, which he called the right time for launch when anticipated DC quick-charging infrastructure (using the CCS protocol adopted by all German and U.S. makers) would be ready.

But industry insiders doubt that Audi will go to the expense that BMW has in developing a unique platform or "architecture" for its electric SUV, which will be a low-volume vehicle for the automaker.

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

Instead, it will likely be adapted from the company's new SUV platforms--whether the Q5 mid-size or the Q7 large SUV that was unveiled in February.

It would thus follow the model of the Audi R8 e-tron, which is adapted from the second-generation R8 two-seat sport coupe.

Audi R8 e-tron

Audi R8 e-tron

Mercedes-Benz is rumored to be developing its own platform--codenamed "EcoLuxe"--for future electric and hydrogen fuel-cell vehicles.

But so far Audi's parent, the VW Group, appears to be sticking with adaptations of existing vehicles and platforms to economize on development costs.

[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.]


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