Today’s all-wheel drive (AWD) systems are smarter, more effective, and faster-acting than ever – and the latest advances in powertrain technology have allowed the average shopper to benefit from world-class AWD performance like never before.
Your next AWD vehicle will likely use a generous helping of high-tech engineering and processing power to provide added traction and control in a wide range of situations – and it’s also likely packing one or more supplemental features that works with the AWD system to help further boost confidence.
Below, we’ll take a look at a few of the most common of these systems. Each is designed to help improve traction and performance, hand-in-hand with your AWD system, in a variety of different ways.
Drive Mode Selector
Many AWD utility vehicles, including pickups and crossovers, include some form of Drive Mode Selector system. Though marketed under various names by various automakers, the premise of the Drive Mode Selector is simple: by using a dial or switch to put the vehicle into the appropriate mode, drivers can pre-emptively tell the vehicle’s various systems what sort of driving is about to be tackled. (Similar in concept to the dials found in sports cars to adjust performance parameters.)
For instance, many such systems offer a special Snow mode, which may improve control by reducing throttle sensitivity, reworking transmission shift points, and recalibrating the front-to-rear torque split of the AWD system. The goal? Providing more bite on slippery surfaces, with less wheelspin, and more overall traction.
Other vehicles have selectable modes like Off-Road, which boosts available traction and torque; or a Sport mode, which improves throttle response and sets the AWD system up for added agility and responsiveness. Just pick the mode you need for the conditions at hand, and the vehicle’s hardware and programming help maximize traction for the precise situation at hand.
Finally, many AWD vehicles with a Drive Mode Selector also include a default Normal or Auto mode, for all-purpose driving, and considers numerous variables to make the best possible decisions on the fly.
AWD Lock
Numerous AWD vehicles include a special AWD Lock mode, typically engaged by the driver at low speeds for use in very slippery and challenging conditions. With the Lock mode engaged, an optimal torque split between front and rear axles is locked in, instantly increasing traction. Instead of waiting for wheelspin or some other trigger to engage maximum grip, using the Lock mode tells the AWD system that maximum grip is required, right away. Use it when driving through deep snow, slippery mud, or when climbing a steep and slippery hill. This system is typically intended for low-speed use, and your owner’s manual has the full scoop.
Hill Start Assist
Getting your vehicle moving from a stop on a slippery or steep hill can be challenging, and that’s whether you’ve got AWD on your side or not. To help keep drivers moving, no matter the conditions, many AWD vehicles include Hill Start Assist, which eliminates the tendency of a vehicle to roll backwards for a moment when setting off on a steep grade.
Hill Start Assist typically engages automatically when the vehicle stops on an incline, and momentarily “freezes” the pressure in the brake lines after the brake pedal is released. This gives drivers time to apply the throttle before the vehicle rolls backwards, meaning there’s less momentum to overcome to get moving ahead, and less likelihood of spinning the wheels or becoming stuck.
With Hill Start Assist, which may be marketed under different names by different automakers, you’ve got a helping hand in an extra-challenging situation, and significantly improved chances of getting moving again – in the right direction – if you need to stop on an icy incline.
Hill Descent Control
Hill Descent Control is a popular feature in many AWD crossovers these days – typically activated by the driver just before they head down a steep and slippery hill. Where the AWD system extracts the most possible traction from the surface beneath during acceleration, Hill Descent Control works to similar effect – though it’s concerned entirely with maximizing traction in tricky downhill conditions where speedy acceleration is entirely discouraged.
Hill Descent Control uses special control parameters for your vehicle’s brakes, transmission, traction control system, and more. By carefully optimizing each system in real time, Hill Descent Control allows the vehicle to carefully and precisely scale down steep hills, on an inch-by-inch basis. As needed, the system carefully works the brakes on each wheel individually, keeping downhill speeds to a minimum, so the driver can focus on steering.
Hill Descent Control works differently than AWD, but the two go hand in hand – sharing a common goal of delivering absolute confidence.
Selectable Centre Differential
Some specialized performance car models put a unique supplemental AWD feature at their driver’s disposal, by way of a selectable centre differential. In models like the Subaru WRX STI and Mitsubishi Lancer Evolution (RIP), drivers can select from one of several settings that actively controls the behaviour of the centre differential, which is the mechanical heart of the AWD system.
Depending on the application, drivers can select the desired split of engine power between the front and rear axles, or when and how the centre differential locks up in response to changing surface conditions. This allows for fine-tuned control, as well as easier access to the machine’s high-performance capabilities on loose, slippery, or dry surfaces.
Selectable Rear- or All-Wheel Drive
It's a long-held convention amongst many driving enthusiasts that rear-wheel drive (RWD) makes a vehicle feel more nimble, engaging, and dynamic – especially in extreme driving in a motorsports setting. Conversely, in many market segments, it's all-wheel drive that sells cars, thanks to the added traction and confidence imparted during use in inclement conditions.
The latest in AWD technology has recently seen a solution to the AWD vs RWD conundrum. The solution? Offer both, in the same vehicle.
An extension of the functionalities that allow AWD systems to vary the torque split between the axles, select systems on recent models like the Ford Focus RS, BMW M5 and Mercedes-AMG E 63 S actually offer drivers a special setting which disengages the front axles, effectively allowing these AWD vehicles to run continuously in a purely RWD mode, based on driver preferences and current conditions.
The excitement of pure RWD can be engaged when desired, and in bad weather, full AWD functionality can be reengaged at the flick of a button – giving drivers the best of both worlds.
