Alfa Romeo is introducing an innovative self-locking front differential called 'Q2' which it says provides some of the advantages typical of four-wheel drive, but at a significantly lower cost and weight.

The system is now available with the 150 bhp JTDM (turbodiesel) engine on the Alfa GT and 147 models but will subsequently be extended to other models in the Italian automaker's range.

Ongoing development of turbodiesel technology which, since 1997, when the 156 JTD (the first car to adopt Common Rail technology) was launched, has seen a considerable increase in torque delivery to the wheels even on compact cars so Alfa has developed the Q2 system to guarantee maximum control and traction in all driving conditions.

Q2-equipped versions of the 147 and GT are badged as separate models and have interior and interior trim enhancements and additional equipment.

The main element of the Q2 system is a limited-slip Torsen mechanical type differential which splits torque between the front drive wheels dynamically and constantly, according to driving conditions and the road surface.

Alfa said that the system "significantly" increases roadholding, traction and stability on the release, while attenuating understeer on acceleration, the intervention of the electronic control systems and steering wheel vibration.

The improved mechanical efficiency of the Q2 transmission delays the intervention of the vehicle control systems, guaranteeing better traction as the car exits the bend, which makes driving more enjoyable and maintains complete control of the vehicle, the automaker added.

On surfaces with poor grip, the negative effects are reduced by the gradual transfer of torque to the wheel that can exploit the best friction coefficient, simplifying a hill start, for example.