February 2014: The What now? edition

Gas prices are up. There are more hybrid and plug-in vehicle models available to the public than ever. Nissan's doing great with its Leaf and Tesla continues to exceed sales expectations with its Model S. And yet advanced-powertrain and alt-fuel vehicle sales continue to crater compared to the numbers from a year ago. What's going on here?

Americans bought just under 40,400 green vehicles in February, down 23 percent from the almost 52,500 they purchased a year earlier. And, no, there's no leap year to blame here.

We might have to blame Prius fatigue.

We might have to blame Prius fatigue, much to the chagrin of Toyota. The four variants of the world's most popular hybrid model combined to sell 12,861 units last month, down 28 percent from February 2013. Toyota's other hybrid models did even worse, with sales of the Camry, Avalon and Highlander Hybrids plunging 39 percent, 55 percent and 76 percent from a year earlier, respectively. Overall, Toyota's green-car sales dropped 29 percent from a year earlier to 19,027 units.

And General Motors wasn't immune either, despite the recent introduction of models such as the Chevrolet Spark EV, Chevrolet Cruze Diesel and Cadillac ELR extended-range plug-in. Sales of mild-hybrids such as Buick's LaCrosse and Regal and the Chevrolet Malibu eAssist continued to substantially lag last year's figures. The Chevrolet Volt extended-range plug-in moved 1,210 units, down 26 percent from a year earlier. In all, GM saw sales fall 35 percent from a year earlier to just 2,658 vehicles. Ford fared slightly better, as Fusion Energi Plug-in Hybrid and Lincoln MKZ Hybrid sales jumped from a year earlier. But that was more than offset by declines in sales of models such as the Fusion and C-Max Hybrids, bringing Ford's overall sales down nine percent from a year earlier to 6,776 units.

Despite higher gas prices, Americans aren't gravitating to clean diesel models.

And despite gas prices being up about seven percent since the beginning of the year, according to AAA, Americans aren't gravitating en masse to clean diesel models the German automakers are selling. Volkswagen's green-car sales dropped 32 percent from a year earlier to 4,787 units, as low-volume sales of its new Jetta Hybrid was more than offset by falling diesel demand. And Audi's diesel sales dropped 65 percent from a year earlier to 1,048 units.

Only Honda appeared to buck last month's hybrid-sales trend, boosting green-car sales by 52 percent from a year earlier to 2,109 units. The Japanese automaker sold 910 of its new Accord Hybrids, while Civic Hybrid sales were 2.3 percent ahead of year-earlier figures. The Insight was down 12.3 percent and will not be available much longer.

Still, such overall sales declines more than offset gains by electric-vehicle makers like Nissan and Tesla. Nissan Leaf sales more than doubled from a year earlier to 1,425 units. And if Tesla sales maintained their fourth-quarter pace into the new year (the company doesn't release monthly figures), those approximately 2,300 vehicles sold last month would be 45 percent ahead of year-earlier figures.

With such sales gains, US plug-in vehicle sales rose 40 percent from a year earlier to 7,848 units, bringing a slight glimmer to a dark month for green-car sales.