green car salesWe'd say that the U.S. plug-in vehicle market's starting to fire on all cylinders, but then again, cylinders pretty much defeat the purpose, don't they?

Monthly-record sales of the Chevrolet Volt extended-range plug-in and the second-best month ever for the Nissan Leaf all-electric helped spur October alt-fuel vehicle sales to a 76 percent jump over 2011 figures.

Plug-in vehicle sales totaled 6,784 units, the third-consecutive monthly record.

Plug-in vehicle sales totaled 6,784 units, the third-consecutive monthly record. General Motors moved 2,961 Volts, while Nissan sold 1,579 Leafs, which trailed only June 2011's 1,708 units sold in the ranking of top US monthly sales. Ford moved a monthly-record 118 Focus Electrics, while the U.S. automaker recorded its first sales of its C-Max Energy Plug-in Hybrid, tallying 144 units last month. Mitsubishi maintained its low-volume pace with 30 units sold of the i EV.

Overall, automakers sold more than 46,000 alt-fuel vehicles, exceeding the necessary pace for U.S. annual alt-fuel sales to surpass 500,000 units for the first time ever.

Toyota continued as alpha dog, boosting sales by 70 percent compared to 2011.

Toyota continued as alpha dog, boosting sales by 70 percent compared to 2011 to 24,065 units. The Japanese automaker moved 16,774 Prius hybrids, including 3,328 Prius C compacts, 2,768 Prius V wagons and 1,889 Prius Plug-in Hybrids. Toyota also sold 2,986 Camry Hybrids, while the automaker's Lexus badge boosted hybrid sales by 46 percent from a year earlier to 3,792 units.

Along with record Volt sales, GM more than tripled year-earlier alt-fuel sales to 5,710 units, including more than 2,500 of its mild-hybrid Buick LaCrosse, Buick Regal and Chevrolet Malibu eAssist models.

And Ford continued to close the year-to-date gap from 2011's alt-fuel totals by more than doubling October sales to 4,727 units. Most notably, Ford's C-Max Hybrid wagon, which was launched to compete with the Prius V, beat the latter model's October sales with 3,035 units sold. And while Ford Escape Hybrid sales virtually disappeared (the discontinued model sold nine units last month), Ford Fusion Hybrid sales rose 12 percent from a year earlier to 956 units, while Lincoln MKZ Hybrid sales were little-changed from a year earlier at 465 vehicles.

German-made diesel models also enjoyed sales increases as US consumers looked to cut back on fuel consumption. Volkswagen diesel sales jumped 43 percent from a year earlier to 8,235 units, while sales of Audi diesels rose 18 percent to 581 vehicles. And Porsche increased its hybrid sales total by 27 percent to 154 units.

In fact, the only automaker to experience an alt-fuel drop from a year earlier was Honda.

In fact, the only automaker to experience an alt-fuel drop from a year earlier was Honda, whose 966 units sold marked a 23 percent drop. Civic Hybrid sales were little-changed from a year earlier at 453 units, but CR-Z sales were down 16 percent from a year earlier and the Insight plunged 49 percent to 251 units. Still, Honda's October lag was narrower than its year-to-date alt-fuel sales drop of 46 percent.

Looking at 2012 alt-fuel sales through October, automakers have sold more than 446,000 vehicles, up 67 percent from a year earlier.