The Chevrolet Volt plug-in hybrid again took the crown among plug-in electric cars whose makers report monthly sales.

A total of 2,132 Volts were sold in March, bringing its three-month sales to 5,563 units, higher than any other car with a plug over the same period.

Its stablemate, the Chevy Bolt EV electric car, however, logged only 978 sales, a disappointing number for the 238-mile electric car now in the process of a lengthy national rollout.

DON'T MISS: Plug-in electric car sales for Feb: Volt outsells Prius Prime, Bolt EV, Leaf

The underwhelming nature of the Bolt EV sales is indicated by a comparison to those of the aging, soon-to-be-replaced, much lower-range Nissan Leaf.

Sales of the Leaf last month totaled 1,478, its best total since December—and 50 percent higher than those of the Bolt EV.

To be fair, however, Nissan likely accomplished that number with very high incentives; reports of discounts as high as $6,000 to move Leafs have trickled in over the past few months.

2017 Toyota Prius Prime Premium

2017 Toyota Prius Prime Premium

Toyota delivered 1,618 Prius Prime plug-in hybrids, or 16.6 percent of all Priuses sold last month, a remarkably high proportion.

The Prius Prime still lagged the Volt, but it outsold every other plug-in electric vehicle whose sales are reported.

Overall sales of the Prius hybrid hatchback are down significantly from its pinnacle a few years ago, which boosts the plug-in version's percentage in comparison.

READ THIS: Tesla delivered 25,000 electric cars in Q1 2017, plus or minus

In fact, as reader Charlee Smith of San Luis Obispo, California, points out, 5,865 conventional Ford Fusion Hybrid sedans were delivered last month—just edging out the 5,795 (non-plug-in) Prius hybrid hatchbacks for the same month.

That points to the continued weakness of the fourth-generation Prius, with EPA ratings up to 56 mpg combined, in the face of continued low gasoline prices along with some buyer resistance to its polarizing exterior styling.

But back to cars with plugs: Ford's Energi plug-in hybrid models racked up 1,002 sales for the Fusion mid-size sedan with a plug, and 662 for the C-Max compact tall hatchback, both numbers roughly on average. 

2017 Volkswagen e-Golf

2017 Volkswagen e-Golf

Among other high-volume plug-in cars, 342 Volkswagen e-Golfs were delivered, a low number for the all-electric version of the Golf hatchback.

The upcoming 2017 e-Golf will offer 50 percent more range, with an EPA rating of 125 miles, making the declining sales of the lower-range version less remarkable.

Proving that point, sales of the BMW i3 returned to 703 units last month, as the first 2017 models with longer range were delivered, following a couple of much lower months in the 300s.

CHECK OUT: Lessons learned from early electric car: 2011 Nissan Leaf at 90,000 miles

The updated 2017 Ford Focus Electric, with 114 miles of range, surged in sales last month, logging 407 deliveries—its best month in more than five years on sale, following a high 228 last month.

Tesla delivered 25,000 electric cars during the first three months of the year, but that's a global figure and its U.S. sales were not specified.

2017 Tesla Model S

2017 Tesla Model S

As always, Tesla refuses to release monthly sales data by country as other makers do.

One outlet using different data to estimate Tesla's U.S. sales suggest that the domestic number has fallen substantially from a year ago, but that can't be confirmed with the company.

Audi, meanwhile, delivered 414 A3 e-tron plug-in hybrid hatchbacks, its second-best month ever.

Fully 25 percent of the Audi A3 luxury compact cars delivered this year have been the plug-in hybrid, a very high percentage among mainstream makers.

2015 Porsche Cayenne S E-Hybrid, 2014 Paris Auto Show

2015 Porsche Cayenne S E-Hybrid, 2014 Paris Auto Show

Among lower-volume plug-in vehicles, Mercedes sold an average 50 B250e all-electric hatchbacks, and its plug-in hybrids logged 60 (S-Class large sedan), 47 (GLE crossover utility), and 17 (C-Class smaller sedan) respectively.

Porsche delivered 126 Cayenne S E-Hybrid plug-in hybrid crossovers and 3 remaining Panamera S E-Hybrid, before the latter four-door sedan is replaced by an entirely new plug-in hybrid model with standard all-wheel drive.

Mitsubishi sold 3 more i-MiEVs, Cadillac delivered 3 last ELR range-extended electric luxury coupes, Smart sold 13 more ForTwo Electric Drives before a new generation arrives this summer, and BMW sold 48 i8 plug-in hybrid gullwing coupes.


Follow GreenCarReports on Facebook and Twitter.