While U.S. vehicle sales last month are expected to fall overall as data rolls in, August has traditionally been a very good month for sales of plug-in electric cars.

The Chevrolet Volt, for one, kept up its pace this year, with August sales of 2,081, for an eight-month total of 14,295 Volts delivered so far this year.

The Nissan Leaf, on the other hand, continued at the markedly slower pace it's seen over the past two years, with 1,066 delivered last month for a year-to-date total of 7,922.

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The third best-selling electric car in the U.S. has been the Tesla Model S. But Tesla Motors refuses to release sales data broken down by country or month, so we do not have access to comparable data for its two vehicles.

The fourth is a plug-in hybrid version of the Toyota Prius hybrid; the old one went out of production last year, but the new 2017 Toyota Prius Prime should show up in sales toward the end of this year.

After more than five and a half years of steadily increasing year-over-year sales that began in September 2010, the overall U.S. market has now experienced four declines over the past six months, indicating that its growth has plateaued.

2016 Nissan Leaf

2016 Nissan Leaf

But plug-in cars experienced their plateau last year, selling slightly fewer in 2015 than they did in 2014.

While this year's trend is upward, many electric-car buyers appear to be waiting for new, mass-priced 200-mile entries that will arrive over the next couple of years.

The first will be the 2017 Chevrolet Bolt EV, which is to go on sale in limited regions during the fourth quarter of this year.

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It will likely be followed by a 200-mile version of the next Nissan Leaf sometime during 2017, and the Tesla Model 3 whenever that electric sedan goes into production.

Tesla Motors says the Model 3 will be rolling off the assembly lines before the end of next year, but the industry remains somewhat skeptical.

The other high-selling plug-in cars, which we presently define as more than 300 units a month, are the BMW i3, the Chevy Spark EV (the Bolt EV's predecessor), and the Volkswagen e-Golf on the battery-electric front.

2017 BMW i3

2017 BMW i3

BMW delivered 1,013 i3s last month, only its second four-figure total of 2016. That brings its year-to-date total to 5,372.

While that's lower than last year's comparable number of 6,183.not surprising given the imminent launch of the new 2017 version with 114 miles of rated range, fully 50 percent more.

2017 Volkswagen e-Golf

2017 Volkswagen e-Golf

The VW e-Golf had its highest month since last December, delivering 454 units for a 2016 total to date of 2,253.

Meanwhile, the Chevy Spark EV saw August sales of 292, bringing its eight-month total to 2,404.

While those are still close to compliance-car numbers, the Spark EV is now in effect holding the fort for Chevy until it launches the Bolt EV sometime before the end of this year.

Plug-in hybrids

As for plug-in hybrids, the high sellers include the Energi versions of the Ford C-Max compact hatchback and Fusion mid-size sedan, along with the Audi A3 e-tron Sportback.

The pair of Fords sold 707 and 1,422 respectively, bringing their eight-month totals to 4,687 and 9,998—meaning that Ford has sold more Fusion Energis this year than Nissan has sold Leafs.

The Audi A3 e-tron, meanwhile, continues to deliver steady volumes between 300 and 400 a month. The August number was 346, for a total of 2,637 this year so far.

Smart Fortwo Electric Drive and Mercedes-Benz B-Class Electric Drive at driving school.

Smart Fortwo Electric Drive and Mercedes-Benz B-Class Electric Drive at driving school.

Lower-volume entries

Following those vehicles is a much longer list of lower-volume all-electric and plug-in hybrid cars, most only on sale in limited areas of the U.S.

Battery-electric cars in that category include the Ford Focus Electric (75 sales), the Mercedes-Benz B250e (57), the Smart ForTwo Electric Drive (55 sales), and the Mitsubishi i-MiEV (a comparatively whopping 25).

Totals for those four cars during 2016 thus far are now 579, 417, 483, and 65.

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A new crop of plug-in hybrid utility vehicles shows up too, among them the BMW X5 xDrive 40e, Mercedes-Benz GLE 550e, the Porsche Cayenne S E-Hybrid, the Volvo XC90 T8 'Twin Engine.'

Regrettably, we have data only for the GLE 550e, which sold 24 units in its third month on sale, for a total of 73 to date.

Miscellaneous coupes and sports cars include the BMW i8 (145 sold, for a total of 931 so far) and the all-but-defunct Cadillac ELR, of which just six were sold last month for a 2016 total of 517.

2015 Mercedes-Benz S550e Plug-In Hybrid

2015 Mercedes-Benz S550e Plug-In Hybrid

Finally, we have updated sales data for the big, pricey, plug-in hybrid Mercedes-Benz S550e. August deliveries were 30 units, for an eight-month total of 212—far more than initially reported, as it turns out.

We don't have data yet for the Hyundai Sonata Plug-In Hybrid,  or the Porsche Panamera S E-Hybrid—and as usual, Kia refuses to break out Soul EV sales and Fiat does the same for its 500e compliance car.


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