2WD and AWD modes
Fuel consumption very close to that of a regular two-wheel drive vehicle
Depending on driving conditions and control, two-wheel drive (2WD) or all-wheel drive (AWD) mode is prioritized.
When there is good control, Addidrive hydraulic transmission is deactivated:
- the pump and hydraulic motors are disengaged and at rest
- no hydraulic fluid circulates in the system.
In this mode of operation, the Addidrive system is completely transparent and is similar to an AWD disconnect transmission. Mechanical losses are minimal and fuel consumption is very close to that of a standard 2WD vehicle.
When control is not so good and a discrepancy between the front and rear axle speeds is detected, the Addidrive system engages instantly:
- the pump, driven by the front differential, sends hydraulic fluid to the motors at the rear
- the pressure rises in the system and torque transfer occurs almost immediately.
As soon as conditions sufficiently improve, Addidrive can be disengaged to return to 4x2, optimizing consumption.
Addidrive Auto Mode
When the Addidrive Auto Mode is activated, either by pushing a button on the dashboard or when the vehicle is started, the Addidrive transmission is ready to be engaged to move the vehicule from 2WD to AWD.
The decision of engagement - or disengagement - of Addidrive is made based on driving conditions, wheel grip and analysis of information from vehicle's CAN network: wheel speeds, vehicle trajectory, position of the accelerator pedal, etc.
The Addidrive transmission is engaged as soon as necessary in anticipation of road difficulties, and disengaged as soon as possible to minimize fuel consumption.
No control electronics
Hydro-mechanical torque transfer, needing no calculator or specific algorithm
Hydraulic transmission transfers power to the rear wheels without any control electronics.
With continuous and automatic hydraulic pressure variation in the system according to driving conditions, the torque ratio transmitted to the rear wheels is continuously adjusted, letting the front wheels regain control.