General Motors reported sales of 481 Chevrolet Volt plug-in hybrids in May, while Nissan sold 1,142 LEAF electric cars, its highest monthly total this year by far. In all, GM has sold 2,184 Chevrolet Volts in 2011 or 2,510 units since launching late last year. Meanwhile, Nissan, its fiercest electric car competitor, has sold for […]

