A plug-in hybrid is also in the works, but no timeline has yet been set

A plug-in hybrid is also in the works, but no timeline has yet been set

The World Green Car of the Year award candidates were just released yesterday, and Volvo's name appeared on the list 5 times - more than any other brand. Today word has emerged of a range of new hybrid vehicles in the works, complete with rough dates for their release.

Volvo's DRIVe line of concept cars, shown off at this year's Paris Motor Show, are already planned to reach production. These models, like BMW's EfficientDynamics or Mercedes' BlueEfficiency models, make use of a combination of many technologies to optimize fuel efficiency. On the list of tech tricks are: revised gear ratios, smoother aerodynamic profiles and lower rolling resistance tires.

The new hybrids will include a so-called 'micro-hybrid', which feature stop-start technology and will be available with both petrol and diesel engines. Not a hybrid in the traditional sense, it does feature brake energy regeneration, and could yield fuel efficiency improvements of up to 5%, reports Channel4.

Of more technological interest, however, is the diesel-electric full hybrid slated for 2012. Powered by either a D5 diesel engine or electric motors, or some combination of both, the car is expected to deliver up to 15% better fuel efficiency than a typical diesel, many of which already rival petrol-electric hybrids. A plug-in electric hybrid with 60mi (96km) electric-only range, likely based around the ReCharge concept (pictured), is also in the works.

Until the new spate of hybrid technologies arrives, however, Volvo will busy itself with a range of other improvements, including direct injection, due to begin rolling out in 2009. U.S. availability of these advances and the hybrid models is still not yet known, and with the ongoing potential sale of Volvo by Ford, Ford's own economic difficulties in the U.S. and the general state of the industry, anything could yet happen.