OFF ROAD PERSONALITY FOR LEISURE TIME
 

The Fiat Sedici was created to overcome any on-road situation without ever stooping to compromise. This is evident in its rigid, reinforced chassis and also the adoption of electronically-controlled 4x4 drive that distributes variable torque to front and rear wheels. In particular, the Fiat Sedici adopts a new on-demand 4x4 system with central differential and 3 operating modes that combines the performance of a true off-roader with the driving comfort of a road vehicle. It represents a blend of four wheel drive and front wheel drive systems and therefore exploits the best of both these systems. Under normal conditions, the Fiat Sedici system therefore behaves like a transmission with two drive wheels with the benefit of lower fuel consumption and lower emission levels. When road conditions decline and grip is lost, the system acts as a 4x4 transmission, automatically modulating torque distribution between the front and rear axle to increase vehicle safety.

The heart of this specific transmission is an electric dry multi-plate clutch coupling system (operated by an electromagnet) that modulates the transferred torque electronically according to the need for traction. More specifically, the electrical pulse that generates the magnetic field to couple the plate arrives when the ABS sensors detect relative slip between front and rear wheels. This allows the system to change over from a 2WD to a 4WD transmission simply and quickly: all you have to do is operate a key on the dashboard to select one of the three operating modes (2WD, AUTO and LOCK) without the need for a separate gear lever.
 

More specifically, only the front wheels transmit torque with the 2WD function. The 4x4 is not engaged and there are no dissipation effects. This mode is better suited for normal driving conditions (dry road) and to achieve the lowest possible fuel consumption. The second function is AUTO: in most cases, the torque is transmitted to the front wheels. The distribution of torque between front and rear is controlled automatically. The system supplies optimum torque to the rear wheels when the sensors detect low grip and also to anticipate a loss in traction (e.g. during acceleration).

In LOCK mode, torque distribution is locked to ensure prompt, stable take-off under extreme conditions (sand, mud and snow). Under these conditions, the torque distribution ratio is 50 to 50 between front and rear axles. This mode is maintained up to 60 km/h and then transfers to Auto mode to ensure a more comfortable drive. Due to this specific four-wheel drive system and a minimum ground clearance of 19 centimetres, the new model can cover uneven, difficult ground with ease, as the ramp angle values reveal (standard A). Firstly, the rear incidence angle (31.1°), which is the maximum gradient climbable in reverse from a horizontal plane. Next comes the slope angle (18.1°), i.e. the maximum possible angle at the base of a triangular slope (isosceles) if it is to be driven up without the bottom of the car touching the ground. Last is the front incidence angle (20.3°), a measure of the maximum front angle that may be tackled by an off-road vehicle without the body touching the ground.