Diesel hybrids are now no longer a new concept--even if none are sold in the U.S.--but Swedish carmaker Volvo is the only company offering a diesel plug-in hybrid.

That car, the Volvo V60 Plug-In Hybrid, is now in full production at the maker's Torslanda plant in Gothenburg, Sweden.

Volvo V60 Plug-In Hybrid: First Drive Video

The Plug-In Hybrid has required parts of the factory's final assembly line to be modified, accommodating the 300 extra components which go into the diesel plug-in.

The electric motor and driveshafts are assembled at the same station as the firm's all-wheel drive models, while cooling and high-voltage cables are fitted along with the rest of the drivetrain and chassis parts.

The 11.2 kWh lithium-ion battery, which provides a range of up to 32 miles on electric power, is inserted through the tailgate before being rotated and installed below the trunk floor.

First diesel plug-in

While Mercedes-Benz now offers a diesel full-hybrid and Peugeot-Citroen has a range of diesel through-the-road hybrids, Volvo is the first company to offer a plug-in option using a diesel engine.

The setup uses a 2.4-liter, five-cylinder turbo-diesel and six-speed automatic transmission to power the front wheels, while a 52-kilowatt motor supplies the rear wheels. That makes it a through-the-road hybrid just like the French vehicles, but the Volvo is able to run on battery power alone for much longer.

Like the Peugeots and Citroens, it also means extra traction in cold weather, or when accelerating hard--62 mph can be reached in under 7 seconds.

Better still, claimed fuel economy is as high as 124 miles per gallon--on the optimistic European cycle, at least. Bank on a realistic 100 mpg, with a full charge of the battery taken into account.

The car has already been in demand, with the first run of 1,000 cars selling out before it reached showrooms. Production will now step up to 4,000-6,000 cars per year.

Sadly, none of those will be coming Stateside--just like the other diesel hybrids out there, this one is Europe-only.

Still, maybe that isn't so bad--diesel hybrids don't make as much sense as you think...

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