Volkswagen today unveiled a concept crossover sport utility plug-in hybrid diesel called the CrossBlue at the 2013 Detroit Auto Show. If put into production the automaker says the concept vehicle would slot in between the Tiguan and Touareg.

The plug-in hybrid powertrain mates the German automaker’s TDI diesel engine with two electric motors, a 54-horsepower front electric motor and 114-horsepower rear electric drive motor, to a dual-clutch automatic transmission. It also features an all-electric all-wheel drive mode the company refers to as “propshaft by wire.”

Volkswagen estimates fuel economy for the CrossBlue at 89 Miles Per Gallon Equivalent (MPGe) combined in electric mode, and 35 mpg as a hybrid. VW says the powertrain produces up to 305 horsepower and 516 pound-feet of torque, with 0 to 60 mph estimated to take 7.2 seconds.

The CrossBlue runs in zero emissions mode either at the press of a button or automatically.

With a fully charged 9.8-kilowatt-hour lithium-ion (li-ion) battery, the CrossBlue can travel a distance of 14 miles in all-electric mode; to achieve optimal driving range, the top speed is reduced from 127 mph to 75 mph. VW says overall driving range is 661 miles if the 18.5-gallon fuel tank is filled with ultra-low-sulfur diesel fuel.

The concept PHEV diesel has two “fuel doors” – the filler neck for the diesel tank on the passenger side, and two electrical sockets behind the door are on the driver’s side. The first socket is used to charge the li-ion battery, and the second can be used to connect electrical devices, with the concept car acting as an auxiliary electrical generator.

In concept form the car has six individual seats in three rows, but in a production version the second row would have the option of three seats to make it a full seven seater.

Propshaft by wire

All four of the CrossBlue’s wheels are driven whenever off-road mode is intentionally activated, says VW.

In off-road mode the front electric motor is powered by the TDI engine, and operates exclusively as a generator and a power source for the electric motor at the rear. Volkswagen explains that since power for driving the rear wheels is electrical rather than mechanical, the drive mode is referred to as “propshaft by wire.” Because the TDI engine drives the front wheels in off-road mode, the four-wheel-drive system is still operational even with when the li-ion battery has depleted reserves.

A new VW PHEV for America

“The CrossBlue concept is exactly the right type of vehicle for the U.S. market,” said Jonathan Browning, President and CEO, Volkswagen Group of America. “It combines a truly versatile interior layout with sophisticated Volkswagen design, to give a unique and supremely stylish offering in this segment.

VW CEO Dr. Martin Winterkorn has been quoted in reports saying the CrossBlue concept was “developed specifically for US customers,” and if built will be available in American with both gas and diesel engine options, as well as a plug-in hybrid