Saab is planning to introduce a hybrid assist system on its new 9-5, using a small petrol engine backed up by an electric motor in a bid to cut fuel consumption and emissions.
The Swedish company is developing a 9-5 with a turbocharged 1.4-litre petrol engine. This unit will be assisted during periods of acceleration by an electric motor sandwiched between the engine and transmission.
The big advantage of an electric motor is that it offers high levels of torque from idle. In the Saab the electric motor will come on stream when the driver is pulling away or accelerating.
However, when the car is cruising the 120bhp 1.4-litre engine has more than adequate power on its own. The result should be diesel-matching economy with petrol engine refinement, lower pollutant levels and impressive acceleration.
The system works on a similar principle to the drivetrain in the BMW Vision Efficient Dynamics, which has a 1.5-litre diesel powerplant boosted by a pair of motors.
Because the hybrid assist is only used in short bursts, the car’s battery pack can be small and relatively cheap — a key factor, given that Saab wants the 9-5 to undercut its main German rivals.