BMW unveils stunning i8 plug-in supercar

BMW unveiled concepts of two plug-in electric cars today -- the i8 hybrid supercar and the i3 urban electric get-around car -- and it sounds like both are headed for production.

The BMW i8 four-seat sports car concept goes from 0 to 62 mph in less than five seconds and only sips from its backup gas engine. It can drive up to 18 miles on electric power alone before the three-cylinder gas engine kicks in.

Its top-end performance should be breathtaking considering it's a "green" car. It will be electronically governed at more than almost 140 mph.

"The BMW i8 concept is the sports car for a new generation – pure, emotional and sustainable," said Klaus Draeger, a member of BMW's board responsible for development.

The i3, by contrast, is a small, pure-electric car designed to go about 80 miles between charges. It is specifically designed for city use and makes extensive use of carbon fiber to cut weight by more than 500 pounds over a conventional four-seater. It will be capable of 0 to 62 mph in less than eight seconds and can be recharged in less than an hour with a high-capacity charger.

Both the BMW i3 and the BMW i8 will be built at BMW's Leipzig plant in Germany, starting in 2013.