The arrival of a moderately-priced battery electric car with a rated range of 200 miles will change the entire market for plug-in vehicles.

When that will happen, and from which maker, remains open--though the likely suspects are Nissan, Tesla, and General Motors, with BMW as a long-shot outsider.

With GM's then-CEO Dan Akerson having referred to a $30,000 200-mile battery-electric car several times last year, the rumor mills began to buzz.

DON'T MISS: 2016 Chevrolet Volt To Launch Next Year: What We Know So Far

But we haven't heard much lately about such a car, except for an interesting rumor last month: that it will actually be not a dedicated vehicle, but an addition model added to the current Chevrolet Sonic subcompact line in 2016 or 2017.

[UPDATE: After further discussion with sources, this article has been updated in several places to clarify that the 200-mile electric car will be an adaptation of the current Chevy Sonic vehicle, not of the next generation--which is scheduled to be introduced for 2018.]

2015 Chevrolet Sonic

2015 Chevrolet Sonic

That news came via The Truth About Cars, and was not attributed to a named source. In discussions with the writer, the source was identified only as a person within the industry.

After some further investigation, we've uncovered another possible bit of information--which must also, regrettably, remain unsourced: There may be as few as 1,800 Sonic EVs produced over a two-year period.

That wouldn't make it any kind of competitor to much of anything.

Until we learn more, here's our roundup of what we know so far about GM's supposed 200-mile electric car.

TIMING

We know already that the 2016 Chevrolet Volt range-extended electric car will be unveiled to the world at January's 2015 Detroit Auto Show, and go into production in the second half of next year.

2016 Chevrolet Volt - first teaser image, Aug 2014

2016 Chevrolet Volt - first teaser image, Aug 2014

The Detroit Show is the most prestigious venue for Detroit makers to unveil new products, so we'd expect a 200-mile electric Sonic EV to be unveiled at a year later, in January 2016.

That would mean its production would likely begin in late 2016, presumably at the same plant where today's Sonic is built in Orion Township, Michigan.

The current generation of Sonic launched in 2011 as a 2012 model, and the next generation is scheduled to be launched as a 2018 model.

COST

GM's then-CEO Akerson referred several times to the 200-mile electric car as one that would be sold for $30,000.

GM CEO Dan Akerson at the Volt battery fires hearing

GM CEO Dan Akerson at the Volt battery fires hearing

That's a full $5,000 less than the target price (before incentives) for the Tesla Model 3 mentioned by CEO Elon Musk.

On the other hand, if the 200-mile GM electric car is a Chevy Sonic, it will be a segment smaller and carry a far less prestigious brand than the higher-volume luxury Tesla car.

ELECTRIC RANGE

Tesla intends to launch its Model 3 third-generation vehicle line in late 2016 and put it into volume production during 2017 (assuming it gets its lithium-ion battery gigafactory up and running in time to provide battery packs for the car).

We know Nissan, meanwhile, will offer its next Leaf with a choice of battery-pack sizes, giving two or even three choices of range to buyers.

ALSO SEE: New 2017 Nissan Leaf: More Details On New Styling, Range

Nissan product chief Andy Palmer has said that ranges of 120 up to 150 miles could be offered.

2015 Nissan Leaf

2015 Nissan Leaf

That's the likely competitive landscape GM faces. It will likely shoot for an EPA-rated range of 200 miles, but would it settle for 150 miles--or whatever the highest-range Nissan Leaf offers in the next generation?

Having heard a reference to the car as a "Leaf burner," we suspect GM will ensure that the car has a higher rated range than the best version of the next-generation Leaf.

The company will likely aim for 200 miles, but could settle for something between 150 and 200--though clearly any number beginning with "2" is better.

VOLUME

This is perhaps the most hotly-debated issue around a GM 200-mile electric car: Will it be a high-volume vehicle, or only built in compliance-car numbers?

Over the last few weeks, Green Car Reports has discussed this issue with a source in the industry--who asked for very obvious reasons not to be identified.

2014 Chevrolet Spark EV - First Drive, Portland, July 2013

2014 Chevrolet Spark EV - First Drive, Portland, July 2013

We understand that a supplier for the 200-mile electric car has been given a production volume of just 1,800 cars over two years.

This could be erroneous; it could be a misinterpretation, or the volume of just the first batch of cars. But it could also represent total planned production--at least of this vehicle in this configuration.

And if it's accurate, it means a Chevrolet Sonic EV would be strictly a compliance car to let GM meet California's zero-emission vehicle mandate for 2017 and 2018.

Though it does beg the question, what battery-electric vehicle will come next from GM--in 2020 or so?

BODY STYLE

The Chevrolet Sonic today is sold as a five-door hatchback and a four-door sedan.

Which of those bodies would be used for a Sonic EV is open to debate, and depends on the volume that will be produced.

If the Sonic EV is to be sold globally, we suspect it would be the hatchback, a body style far more popular for subcompact cars outside North America than the four-door sedan.

Subcompact sedans are a rarity in Europe and some parts of Asia, so we're betting on the hatchback.

If, on the other hand, the volume prediction of 1,800 cars is accurate, then it will be solely a North American compliance car--and Chevy will use whichever body proves easiest to adapt to battery power.

STYLING & BRANDING

If the 200-mile electric car is an adaptation of the Sonic platform, it would likely follow the lead of the current Spark EV and retain the same shape as the gasoline version of the car.

We'd expect revised instruments and controls to reflect those of the next-generation Volt, which will precede it--just as the Spark EV uses many parts of the current Volt interface today.

And externally, we'd expect a blanked-off grille opening with a silver insert that would echo the 2016 Volt's updated styling.

What the U.S. would know as a Chevrolet Sonic EV, by the way, would be called the Chevy Aveo EV in much of the rest of the world (if it were to be sold outside North America).

2014 Chevrolet Spark EV - First Drive, Portland, July 2013

2014 Chevrolet Spark EV - First Drive, Portland, July 2013

The Sonic nameplate is specific to North America, where the previous-generation Aveo was so disliked (and often known only as a rental car) that the model name was retired.

We still don't expect any hamburger or hedgehog tie-ins for the marketing, though.

BATTERY TECHNOLOGY

As of 2015, General Motors plug-in vehicles now all use lithium-ion cells from the Korean maker LG Chem, which is producing them in its Michigan fabrication plant.

The Spark EV, introduced for 2014 with cells from A123 Systems, switched to LG Chem cells for its 2015 model--and the Volt has always used a battery containing LG Chem cells.

Mock-up of LG Chem battery for Chevrolet Volt

Mock-up of LG Chem battery for Chevrolet Volt

So we expect a Chevrolet Sonic EV to use LG Chem cells as well--and that may have been confirmed by a July comment made by LG Chem's chief financial officer.

As reported in Reuters, CFO Cho Suk-jeh said the company will supply batteries in 2016 for an electric car with a range of 200 miles or more.

He did not specify which carmaker it would be for, but the pool of suspects is relatively small.

The cells are likely to be a newer generation than those used in today's Volts, though that car has now had three different cells in its pack since 2011, with changes made to the 2013 and 2015 models as well.

A further revision for 2017 would be on the right cycle for introducing a cell that can hold more energy at a lower cost per kilowatt-hour

GM declines to comment

Green Car Reports asked GM about the predicted volume, which the company predictably declined to give.

"We do not comment on potential future product and volume speculation," said Kevin Kelly, GM's manager of electrification technology communications.

So while we expect to start to learn more about the 2016 Volt this fall, we don't expect anything substantial out of Chevrolet on the 200-mile electric car for a year or more.

The company will likely want to focus all its publicity on a single vehicle: the new, updated, more capable 2016 Chevy Volt that'll be unveiled next January.

The wait for news on a 200-mile electric car may seem like a very long time indeed--and there will be a drumbeat of news about the Tesla Model 3 and the next Nissan Leaf in the meanwhile.

Over to you, Chevrolet.

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