Saab engine offers mixed blessings

Making its world premiere at the recent Stockholm motor show, Saab's BioPower Hybrid Concept is said to deliver zero fossil CO

emissions, enhanced performance and a range of energy-saving features. It does this by combining the use of pure bioethanol fuel and electric power generation for the first time.

Powered by its 260bhp (191kW) two-litre turbo BioPower engine and 53kW electric motors, the concept car — the latest in Saab's 9-3 range — can briefly generate torque values three times greater than its petrol-only equivalent.

Its modular hybrid system features a maintenance-free, 300V battery bank designed to last the lifetime of the vehicle, a 38kW rear-mounted electric motor, a 15kW integrated starter generator and all-wheel-drive with electric power transmission to the rear wheels.

The all-aluminium BioPower engine is modified to run on pure E100 bioethanol fuel and operates in tandem with the electrical power system. This offers fuel-saving stop/start functionality, torque-boosting electric power assistance on demand, an electric-only 'zero mode' for city driving and regenerative braking.

The car also features a spark-ignited direct-injection (SIDI) system for optimum combustion with E100, ensuring the same cold starting performance as a normal petrol engine.

The prototype, a 9-3 convertible with automatic transmission, is expected to achieve 0-62mph (100kph) in 6.9 seconds.

'This project allows us to evaluate and explore the potential of hybrid technology in combination with our existing and already proven BioPower technology,' said Jan-Ake Jonsson, Saab's managing director.

'Although the exact hybrid application shown in this concept does not currently figure in our production plans, the project has been extremely valuable in helping us further our expertise.'

It is the first venture to be announced under a joint investment programme between General Motors R&D and the Swedish government.

This has seen the establishment of a R&D office in Trollhattan, Sweden, focusing on vehicle safety, engine emissions and advanced manufacturing in collaboration with Swedish universities, research laboratories and suppliers.