Will Volvo's 2012 plug-in hybrid also be a diesel?

The maker of some of the world's safest vehicles will soon be the maker of one of the world's most fuel-efficient vehicles. Volvo announced today plans to produce a plug-in hybrid vehicle that will be available in 2012.

"Most car journeys are short trips, for instance to and from work. We will be able to offer a product that fulfills this transportation need. In order to cover longer distances as well, the car will also be equipped with one of Volvo's fuel-efficient diesel engines," Volvo President and CEO Stephen Odell said in a press statement.

The new development will be a joint venture between Volvo and Swedish energy company Vattenfall. Volvo plans to create a plug-in version of an existing model rather than create a new one, and its charging systems will be developed and supplied by Vattenfall.

Volvo has previously stated its plans for a fleet of 10 plug-in hybrids. The Swedish car company did not name which of its existing cars will be the first to go plug-in, but last year Volvo road-tested the ReCharge Plug-in Hybrid, which is based on the C30 coupe platform and uses a diesel engine to power the lithium ion batteries.

A video on YouTube.com (posted by thecarfanatic.com) shows interviews with Volvo and Vattenhall executives explaining the partnership and features a diesel plug-in hybrid Volvo V70 that can travel up to 50 km (31 miles) on a single charge and be charged from a standard wall socket, which would cost Swedish owners approximately 3 euros per 100 kilometer (60 miles). Based on current currency exchange, that works out to approximately 7 cents per mile. The diesel engine uses 2 liters per 100 kilometer m (.5 gallon per 60 miles), according to the video.

Volvo also announced plans to debut three demonstration plug-in Volvo V70s this summer that will be used to gather information on customer driving habits and technology preferences. Vattenfall will be testing various concepts for high-speed home charging and developing a public charging and billing system infrastructure. The power company is also tasked with accelerating the vehicle's charging time. The video shows a 8 kw battery being charged in 5 hours from a standard wall socket.