2015 Nissan Leaf
With the Labor Day holiday imminent--falling well into September this year--industry analysts have expected U.S. new-car sales for August to be less buoyant than they might otherwise be.
But in the lower-volume world of plug-in electric cars, model cycles remain the driving factor.
The first-generation Chevy Volt has been on a long sell-down, and next year's Nissan Leaf--widely expected to offer a longer-range battery--hasn't yet been released.
Last month, a total of 1,393 Nissan Leafs were delivered to buyers and lessees, bringing the yearly total to 12,383.
That's significantly lower than the 18,941 delivered in the same eight-month period last year--reflecting the combination of an aging model, anticipation of an imminent longer-range version, and perhaps low gasoline prices as well.
The Leaf remains the highest-volume plug-in car sold in the U.S., with a total of 84,705 delivered since it went on sale in December 2010.
2015 Chevrolet Volt
As for the Chevy Volt, 1,380 were delivered in August, bringing the year's eight-month total to 8,315.
A total of 81,672 Volts have been delivered since December 2010.
ALSO SEE: 2016 Chevrolet Volt - full review
Both models are likely to make news this month, with details of the 2016 Leaf potentially released in the next 30 days--and the first of the all-new and longer-range Volt plug-in hybrid going on sale before the end of September.
While it will take both of those cars a while to make it to dealers, we expect to see an uptick by December, though plug-in sales are historically lower during the winter.
2015 BMW i3 REx - Driven, Portland OR, April 2015
Meanwhile, August sales of the BMW i3 were 792, roughly where they've been holding this year--for an eight-month total of 6,183.
Almost 12,300 of BMW's innovative electric car--the most energy-efficient vehicle available in the U.S.--have been sold since its launch in May 2014.
Tesla Motors refuses to release standard monthly sales figures by market for its Model S electric luxury sedan, so we can't say how many of that vehicle were sold in August.
Plug-in hybrids: high-volume
As for the plug-in hybrids, the Toyota Prius numbers continue to wane.
2012 Toyota Prius Plug-In Hybrid, Catskill Mountains, NY, Oct 2012
The Prius Plug-In Hybrid production having ended earlier this year--and a new version not due until the end of 2016.
Just 344 plug-in Priuses were delivered in August, its lowest total since February 2012--the very first month it went on sale.
As for Ford's Energi plug-in hybrids, it sold 723 C-Max models and 949 Fusion versions, both modestly higher than the July figures.
Each of the eight-month totals, however--4,959 and 6,091--is down on the total for the same eight-month period last year, however.
Finally, there's the largest number of plug-in cars: those that are low-volume (for various reasons) and the California compliance cars sold solely to hit volume targets imposed by the state for zero-emission vehicles.