green car sales graphic

Heaven help the analyst trying to get a handle on year-over-year green-car sales numbers, because there is little rhyme or reason to them. Just when one would think the usual summertime bump in gas prices may spur more Americans to buy hybrids, plug-ins or diesels, the industry turns in another down month in July.

Green car sales fell three percent from July 2013.

While things perked up slightly from June's 7.6 percent decline, green car sales still fell three percent from July 2013 to 58,010 units. Granted, those numbers didn't factor in Tesla Motors (the plug-in vehicle maker breaks out neither monthly sales nor domestic-only sales), but even factoring Tesla in, green-car numbers would still likely be down.

That's pretty disappointing considering the strong months both the Nissan Leaf battery-electric and Chevrolet Volt extended-range plug-in had in July. Leaf sales jumped 62 percent from a year earlier to 3,019, the second-highest monthly total ever after May 2014's 3,117 units. The Volt had its best month of the year so far, boosting sales 13 percent to 2,020 units. These sales boosted US plug-in sales (again, not including Tesla) by 68 percent to 9,810 vehicles.

Fusion Energi Plug-in Hybrid sales tripled last month, compared to July 2013.

Meanwhile, both Honda and Ford also made progress on the green-car front. Ford's green-car sales rose 16 percent to 7,907 vehicles, as the Fusion Energi Plug-in Hybrid sales tripled from a year earlier to 1,226 units, while C-Max Energi PHEV sales almost doubled to 831 vehicles.

Honda did even better, increasing green-car sales 58 percent to 2,536 vehicles. While Civic Hybrid, Insight and Fit EV sales were all down about 30 percent from a year earlier, Honda moved 1,362 units of its new Accord Hybrid.

As for newer German plug-ins, Smart moved 298 of its ForTwo ED vehicles last month, while BMW sold 363 i3 battery-electrics. Additionally, Audi boosted its diesel sales by 69 percent to 1,298.

And that's pretty much where the good news stops. Toyota's green-car sales were down 3.7 percent to 31,598 vehicles, as sales of its four Prius variants fell 11 percent from a year earlier. That more than offset the 9.9 percent boost in Camry Hybrid sales and the 16 percent rise in Lexus hybrid sales.

Things were even uglier at GM, where green car sales plunged 20 percent from a year earlier to 3,464 units. While the Spark EV and Cruze Diesel joined the Chevy Volt in the positive category, the virtual disappearance of Chevrolet Malibu Eco sales more than wiped all of those gains out.

Volkswagen had a soft month as well, as diesel sales fell 35 percent to 7,220 units.