Volkswagen’s Amarok offers clever engineering as a solution to off-road ability
In out last issue of Delivery, we looked at the general performance of the Amarok single-cab ute that’s currently under evaluation in our test fleet. This time around we are going to take a closer look at the ability of the 4Motion all-wheel-drive system and its overall effectiveness in a variety of off-road situations.
Unlike the conventional 2WD/4WD selection systems of the Japanese-styled utes, there are no transfer levers to push, no hubs to lock in or out, and no other major controls. Selection of 2WD or 4WD, high or low ratio, and differential locks, is all accomplished by a push button on the centre console.
In addition to the standard electronic differential lock, a mechanical differential lock on the rear axle comes standard on 4MOTION models and is available as an option on 2WD versions.
There’s a whole collection of clever electronic systems that combine to improve off-road ability as well as provide very high levels of safety. This is where it’s important for the driver to actually read the instruction manual to find out how the systems work and how to make sure they are switched on before you get stuck somewhere.
It’s our view at Delivery that not getting stuck is a lot better than getting stuck and having to work out a solution to the problem. With the right button pressed, the electronic interventions can significantly affect off-road performance and enable the Amarok to get through a situation that would totally bog down other vehicles. But, like all technology, you need to know what to do and how to use it in order to achieve the best result.
The Electronic Stability Program (ESP) with Brake Assist is standard equipment. Another feature contributing to safety is “Off-Road Mode”. Activated by the press of a button (up to a vehicle speed of 130 km/h) it brings into action the ESP system, electronic differential locks (EDL), anti-slip regulation (ASR) and anti-lock braking system (ABS). Acting together, this combination of technologies provides a significant benefit when driving the vehicle in off-road conditions.
The ABS system can reduce braking distance both off-road and on gravel road surfaces, often significantly depending on the road composition. When “Off-Road Mode” is activated while the ute is driven at less than 30 km/h, Hill Descent Assist is also activated to hold driving speed constant on steep descents by means of targeted brake actuations.
When using Hill Descent Assist, the driver can individually adapt the vehicle’s speed to a driving situation by accelerating or braking. The system is even sufficiently clever that it will continue to control the hill descent speed of the vehicle even if the gear lever is in neutral, working to maintain a safe descent speed by applying brake force to individual wheels.
Admittedly, in this situation there is no additional engine braking provided, but, in test conditions, we found the system works extremely well. Hill Hold Assist ensures that the Amarok does not roll backwards on inclines when the brakes are released.
The design of the front and rear body panels provides an approach angle of 28 degrees (front) and exit angle of 23.6 degrees (28 degrees for vehicles without a rear bumper). The ramp breakover angle is 23 degrees, and the standard wading depth is 500 mm.
The base model has selectable 4MOTION four-wheel-drive, and, as you step up to the Amarok Ultimate, the system is upgraded to the permanent 4MOTION all-wheel-drive system.
The drive system for the permanent 4MOTION models features a central Torsen differential that provides optimal engine power distribution between front and rear axles. Normally, the distribution ratio is 40:60; however, under rugged conditions, power distribution can be varied according to the properties of the road surface.
The basic electronically controlled braking system includes an Electronic Differential Lock (EDL) that automatically acts on all driven wheels, increasing traction especially on surfaces where tyre grip differs on the two sides of the vehicle. In this way, power from the engine is always directed to the wheel with the best traction.
Anti-Slip Regulation (ASR) and engine drag torque control (MSR) are implemented in the versions with two-wheel-drive and selectable four-wheel-drive. When these systems activate on the Amarok with a 2WD system, the ASR and MSR only apply as much torque to the rear wheels as the tyres can transfer to the road surface, based on their grip.
When selecting an Amarok, the buyer has the choice between two different levels of suspension performance. Where high payload ability is not required the buyer can choose the optional comfort suspension. This consists of a 2+1 trapezoidal spring pack that offers softer suspension and minimises any road induced vibration and interior noise levels. The gross vehicle weight rating is up to 2.82 metric tonnes, and, in the case of the Amarok 2WD, this corresponds to a maximum payload of 977 kilograms.
Where higher payloads are required, the buyer can choose the standard Heavy Duty package, where the payload is 1,197 kg and the GVM is 3,040 kg.
This package is standard on the rear-wheel-drive version and on the Amarok with selectable 4MOTION drive. To cope with the higher weights and load stresses, it consists of 3+2 trapezoidal suspension with three primary and two additional spring packs. The front suspension design incorporates a dual-wishbone suspension with cast pivot bearings. The spring displacement of 190 mm gives it special off-road properties, yet also permits high loading.
All versions can tow braked trailers up to 3,000 kg (750 kg unbraked) with a maximum downball weight of 300 kilograms (up to twelve percent grade). The gross combination weight of the vehicle and trailer together may reach up to 5,500 kg. If buyers are intending to tow at peak rates, Volkswagen recommends using the factory-installed towing prep package, which provides an increased engine cooling system.
The electronic control systems also monitor the forces generated through towing a heavy trailer, and interact with the vehicle and trailer to maintain stability and prevent trailer sway.
To achieve stability, braking begins precisely when the trailer passes through the “neutral” or zero position in its swaying motion. The ESP control module counteracts the transverse forces transmitted to the towing vehicle by applying different amounts of braking force to the front wheels in an alternating sequence.
As in conventional ESP control of the curve driving limit, the control module throttles down the engine and initiates braking in a highly complex process. All four wheels are decelerated in a relatively restrained manner: Mildly at the beginning, and, if necessary, more vigorously later.
The addition of the single-cab ute and the chassis/cab versions to the Amarok ranges has been accompanied by some cosmetic changes to specification, with highlights including stainless steel sports bar and side steps now as standard on the Highline model, and Bluetooth mobile phone connectivity, cruise control and a multi-function leather steering wheel as standard across the entire 4MOTION range.
A style pack is also available for the Single Cab that includes body-coloured front bumper, 16-inch alloy wheels and fog lights.