by Jim Kerr
When the going gets tough, the tough get going. This is especially true for off road vehicles. To cover slippery, rough, rocky or muddy terrain, you need a vehicle that is tough. It must also be capable. Recently, I had the opportunity to test out Land Rover’s new Terrain Response system on the 2005 Land Rover LR3. This simple-appearing system helps the driver make the best use of the LR3’s off and on-road capabilities.
Terrain Response uses a rotary knob and two small lever-type switches on the centre console to change the vehicle’s operating characteristics. The system is designed so that a driving program is selected before the vehicle is driven, rather than waiting until there is difficulty in traversing the terrain and then switching it on. In addition, dashboard displays enable the driver to “see” the vehicle in relation to the ground so they can drive accordingly.
The rotary selector knob has several positions. Special off-road programs can be turned off during highway travel but as soon as the driver observes a change in road conditions, the system can be changed instantly. For example, if the roads become icy or slippery, the knob can be turned to the “Grass/Gravel/Snow” position for better traction. If the transfer case is in 4-low mode, the Terrain Response system will also automatically raise the vehicle ride height using the air suspension.
Other rotary knob positions include the “Mud-Ruts”, “Sand” and “Rock Crawl”. During each of these modes, the Terrain Response computer signals several other computers to modify their response. The engine computer changes the electronic throttle response so the driver has a wider range of control. The transmission computer modifies its shift points and gear selection strategies. The Slip Control computer integrates the dynamic stability control, traction control and hill descent control to keep the vehicle moving in a controlled manner. For example, the amount of slip allowed by the traction control is varied dependent upon the driving condition selected. Mud might require more slip while grass and snow have less.
The air suspension is also integrated into the system. For some conditions, the suspension will automatically be lowered or raised. For other settings, such as “Rock Crawl”, the information centre tells the driver to increase the vehicle height. The suspension height control is a small lever to the left of the Terrain response rotary knob while the High/Low range transfer case control is another lever to the right of the rotary knob.
Finally, the Terrain Response computer controls the electronically locking differential in the transfer case and the rear differential for both traction and stability.
On the instrument panel display, the direction of the front wheels is shown to help the driver understand where they are steering. Many off-roaders will sometimes glance out the window or door to check the steering angle because it is easy to lose track of where they are pointed when driving in slippery mud or deep snow. Now they can check on the dash. If the vehicle has the optional navigation system, the screen display will also show the position of each tire in relation to the ground. On bumpy terrain, each tire has a different load on it and different traction. By looking at the display, the driver can see which
tires are loaded the most and drive accordingly to provide the best traction.
Terrain Response is a benefit to both experienced and inexperienced drivers travelling off-road. True, an experienced driver will read the ground and be able to set any vehicle’s controls for best operation, but there are often some limitations. The Terrain Response system allows a wide variety of vehicle configurations, unlike many other 4×4 systems that only allow the selection of two-wheel drive or four-wheel drive modes.
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For inexperienced drivers, Terrain Response automates many of the individual settings to that vehicle control is optimized. Also, if you forget to change something, it will remind you on the driver’s information centre. Does it work? You bet. I tried it over rugged rocks, through rutted and slippery mud trails and during tight turns on hard road surfaces. Each setting allowed the LR3 to easily drive the trails with a minimum of wheel spin and without dragging. Best of all, compared to most other 4×4’s the LR3’s Terrain Response provided a comfortable ride so that I wasn’t all beat up at the end of the day.
I know many experienced 4x4ers may scoff at a vehicle system that uses a computer to automatically control the vehicle’s off-road settings, but the Terrain Response system allows the driver to concentrate on where they are going and enjoy the ride.