The all-new Subaru XV was launched with standard fitment of their superior terrain driving system called X-Mode.
In this specially made roller-ramp demonstration, three out of four wheel contact corners are on free spinning rollers, to simulate slippery conditions. Only the rear-left corner is covered with the steel plate.
When the wheels of the XV are on the rollers and the driver applies the throttle, the front wheels and rear right wheel are spinning freely, while the rear left wheel has zero rotation.
After a few seconds of wheel slipping, the rear left wheel suddenly begins moving and slowly moves the XV forward and clear all the rollers. How does the XV do it? Let’s take a quick look at this sophisticated control system.
What is the X-Mode?
X-Mode is not entirely new, as this system has already been included in the mid-sized Subaru Forester.
The X-Mode is an advanced programme that controls the parameters below to get the XV across slippery terrain and steep inclines:
- Engine torque
- Transmission ratio
- All-wheel drive
- Individual wheel brake control
- Vehicle Dynamics Control
How does it work?
When X-Mode is activated through the press of a button, the engine response is relaxed, so that the driver can better manipulate the accelerator pedal.
The transmission is set to low range, and the all-wheel drive coupling force is increased for better delivery of torque to all four wheels for increased traction.
Once X-Mode detects wheel slip at any of the wheels, the Vehicle Dynamics Control goes into “Enhanced Differential Control” mode. The abnormal speed difference between left and right wheels means that one wheel is slipping, hence X-Mode will apply individual brake pressure on that slipping wheel, and the torque is transferred to the wheel with most traction to provide forward movement.
In the roller ramp example above, the control unit receives signal that there is an abnormal speed difference, thus concluding that the vehicle is slipping.
With the rear left wheel having zero rotation, it also means this wheel has the most resistance, therefore potentially highest amount of traction.
The X-Mode system through the VDC then applies brakes on the slipping wheels, and majority of engine torque is channelled to the rear left wheel for maximum effective propulsion.
All the driver needs to do is control the accelerator pedal and the system will slowly creep the XV forward. Easy.
X-Mode also automatically engages hill descent control. The system automatically controls brake pressure which allows the XV to gently descend at speeds below 20 km/h.
Subaru’s X-Mode is available exclusively on the all-new XV, the Forester and the flagship Outback. The only other SUV that has this feature is the Nissan X-Trail 2.5, called Active Brake Limited Slip (ABLS), which is at a higher price point of RM159,200.
Being fitted as a standard feature, the Subaru XV definitely offers the best value for money for performance on the highway and some fun in the unpaved path. Read more about our review on the all-new Subaru XV here.