Major dynamic advances introduced for the Land Rover Discovery 4 include revised suspension architecture, improved steering, larger brakes and enhanced versions of Land Rover's award-winning Terrain Response and Hill Descent Control systems.
The list of changes starts with new suspension knuckles, designed to reduce the separation between the suspension roll centre and the vehicle's centre of gravity (reduction of 42mm at the front and 62mm at the rear). This dramatically reduces the vehicle's natural body movements when cornering. These roll rates are further controlled by a stiffer and larger anti-roll bar.
In addition, new bushes and new front and rear dampers enhance ride quality.
Increased Stopping Power
A new, larger brake system has been introduced along with the new engines, to cater for the Land Rover Discovery 4's enhanced performance and to improve braking feel.
This new system is derived from the four-piston, opposed-calliper performance system used on the Range Rover Sport. It employs a 360mm ventilated front disc with a new, cast iron twin-piston sliding calliper - which serves to reduce the size of the front brake package while preserving its stiffness, which in turn helps achieve excellent pedal feel.
An additional advance to the braking system is the new emergency brake light function. When the vehicle undertakes severe or emergency braking, the brake lights flash, to reduce the risk of rear end collisions.
More Control In The Bends
A refinement to the understeer control system helps automatically slow the vehicle if taking a bend too fast, enhancing driver control.
The system operates according to steering inputs from the driver. In extreme cases, automatic braking intervenes to reduce the vehicle speed, with the braking pressure level applied according to the steering inputs. Automatic braking up to 'emergency stop' may be applied, if the inputs demand.
Updates For Award-Winning Terrain Response and Hill Descent Control
For the Land Rover Discovery 4, Land Rover's award-winning Terrain Response system gains new features and refinements, further extending the vehicle's all-terrain capability. Terrain Response optimises the vehicle set-up for virtually all on-road or off-road driving situations, with five different settings to suit different terrains: General driving, Grass/gravel/snow, Sand, Mud and ruts and Rock crawl.
For soft sand - one of the most power-hungry surfaces - 'sand launch control' has now been introduced, which makes for noticeably easier drive-away. New, speed-dependent wheel-slip targets for the traction control system permit only very limited initial wheel-slip, helping to prevent the wheels digging down into the sand.
When picking a drive route through boulders, severe articulations can lead to the vehicle leaning in an undesirable direction, calling for simultaneous brake and accelerator engagement. New for the Land Rover Discovery 4, revisions to the rock crawl program improve brake and traction control response times, helping to reduce the vehicle's tendency to roll when traversing boulders and giving a more composed drive through rocky terrain.
Land Rover's much-acclaimed Hill Descent Control system is enhanced on Discovery 4 with the addition of Gradient Release Control. This inhibits the initial rate of acceleration when descending very steep inclines, to increase control and eliminate the potentially alarming lurch which can occur when braking is released at extreme angles.
The system operates automatically whenever Hill Descent Control is engaged; temporarily maintaining brake pressure after the driver releases the brake pedal. It then progressively eases braking pressure to control vehicle momentum and acceleration. Once the vehicle's target off-road speed is achieved, Hill Descent Control operates to take vehicle to the bottom of the slope in its customary composed manner.Published 8 April 2009