Edited from http://en.wikipedia.org/wiki/Chevrolet_Volt
The Vauxhall Ampera is a plug-in hybrid electric vehicle. It operates as a pure battery electric vehicle until its plug-in battery capacity drops to a predetermined threshold from full charge. From there its internal combustion engine powers an electric generator to extend the vehicle's range as needed. When the engine is running it may be periodically mechanically linked (by a clutch) to a planetary gear set, and hence the output drive axle, to improve energy efficiency. The regenerative braking also contributes to the on-board electricity generation. Under the United States Environmental Protection Agency (EPA) cycle, the 2013/14 model year all-electric range is 38 mi (61 km), with a combined electric mode/gasoline-only rating of 62 mpg-US (3.8 L/100 km; 74 mpg-imp) equivalent (MPG-equivalent).
The car has won several awards, including the 2009 Green Car Vision Award, 2011 Green Car of the Year, 2011 North American Car of the Year, 2011 World Green Car and 2012 European Car of the Year.
By Dominic Alves [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons