Jaguar is well underway in the development of its next-generation XJ saloon and despite the company’s financial hardship the car is still on track for a debut in the second half of next year. For the current XJ, Jaguar looked to its past for inspiration and this definitely hurt its sales, especially when compared to rivals like the Mercedes Benz S-Class and BMW 7-series, which have shunned conservative styling in favor of a much more dynamic look.

Jaguar won’t be making the same mistake again. This time around designers are going for a more radical look, borrowing lines from the XF but with even more aggression. However, it isn’t just the styling department kicking it up a gear as the new XJ is also expected to benefit from some very advanced powertrain features.

Thanks to a £307 million loan from the European Investment Bank, Jaguar, together with Land Rover, will develop a raft of new hybrid technologies for its future models. While Land Rover is expected to use a more conventional hybrid system like the one in the Toyota Prius, where both an electric motor and internal combustion engine drive the wheels, the system planned by Jaguar will be similar to the set-up in the upcoming Chevrolet Volt.

Speaking with Drive, Jaguar’s chief engineer Kevin Stride confirmed the company was working on a plug-in hybrid drivetrain that will use an internal combustion engine to act as a back-up generator for an electric motor, rather than the main source of power.

Stride explained that conventional hybrid systems, such as those used by Lexus, are “inefficient”. He said this was “because a petrol engine isn’t as efficient as an electric motor. You want your most efficient motor driving the wheels.”

Furthermore, conventional internal combustion engines are most efficient when running at a constant RPM, and this is how it would be set up as a back-up generator in Jaguar’s future plug-in hybrid drivetrain. When revved hard, Lexus and Toyota’s hybrid engines provided few benefits over conventional petrol units, Stride said.

Other green technologies being developed at Jaguar include engine stop-start and brake-energy recovery systems.