All wheels drive but what is AWD?

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Take, for instance, the all-wheel-drive (AWD) system. It ensures that all four wheels in a vehicle gain traction independently of each other for optimum traction and handling prowess, a common technology used in most SUVs and other cars. 

The history books tell us Daimler’s Dernburg-Wagen was the first automobile to wield an AWD system in 1907. The system has since been adopted by car manufacturers as the best technology for enhanced traction and safe, assured progress.

As a system to keep you safe and intensify your confidence behind the wheel, we take a look at the AWD systems in Volkswagen’s 4Motion, Merc’s 4Matic, BMW’s xDrive, the Audi Quattro system, Porsche Traction Management, Toyota GR-Four and Subaru’s Symmetrical AWD. They all pretty much do the same thing, the difference being the application of each as per the manufacturer’s setting. 

Volkswagen 4Motion

The Volkswagen 4Motion AWD is available in two systems, which do the same work, yet differ in application. One system uses a central electro-hydraulic coupling that bears the Haldex clutch nameplate. It is a system fitted in cars with transverse engines, such as the Volkswagen Golf R and Tiguan. It is regarded as light and economical. 

Then there is the more complex mechanical 4Motion system. It drives vehicles with longitudinal engines, such as the Touareg SUV and Amarok, and uses a mechanical torque-sensing centre differential. The system has proved to work wonders off the beaten track. Think of it as more of a 4×4 approach.

The 4Motion system works hand in hand with the anti-lock braking system (ABS), electronic stability control (ESC) and traction control, all of which are linked by a sensor array that analyses and adjusts according to road conditions. If it detects a slip in one of the wheels, the 4Motion adjusts power and increases grip on the wheel that needs it the most. 

Mercedes-Benz 4Matic

An invention that has been part of the brand for many years, the 4Matic system of the three-pointed star marque has been vastly improved over the years. It is different from other AWD systems that allow drivers to get unmatched levels of grip on the road, thanks to innovative technology that adjusts power delivery to each wheel accordingly. 

The 4Matic AWD works conjointly with the same sort of sensors used by the ABS and electronic stability program (ESP) systems to dictate when a specific wheel loses traction and applies braking pressure to it, thus sending power to the wheels with the most traction. 

Mercedes-Benz’s high-performance models use a 4Matic+ system that has been tweaked and tuned for performance driving, giving drivers the option to channel all power to the rear axle for optimum sideways fun on the track. 

BMW xDrive 

BMW models are equipped with the xDrive AWD technology which guarantees traction in poor driving conditions. In everyday driving situations, the BMW xDrive system distributes power between the front and rear axles in a 40:60 ratio but changes as soon as the system detects a change in road conditions. It can even channel all the oomph to one axle, if necessary. 

The technology uses dynamic stability control to regulate the AWD system when oversteering and understeering occurs. Drivers can choose between drive variants 4WD and 4WD Sport. In DSC-off mode, all power is sent to the rear axle, making the BMW fully RWD. 

Audi Quattro 

Probably the most concise description of the AWD system, if you know Italian. Quattro means “four”, and it’s trademarked by Audi. The Quattro AWD system applies or adjusts power to the wheels for the best traction, thanks to an innovative electronic control system. 

The Quattro system uses intelligent software and sensors that work hard to monitor the steering angle, traction, stability control and the movement of the wheels and distribute power accordingly to ensure no loss of traction. 

High-performance Audi models use the same technology for the additional grip that comes with having all four wheels driven. 

Porsche Traction Management 

Porsche Traction Management (PTM) works to give drivers enhanced driving dynamics, improved safety and superb traction by distributing torque between the front and rear axles as it monitors driving status. 

Unlike other AWD systems, the PTM can be pre-set to respond to different road situations. Using sensors and driving dynamics systems, the system monitors each wheel’s speed and lateral acceleration to change axle load to allow the tyres to have varying degrees of force.  

Toyota GR-Four 

The newest nameplate in the world of AWDs, the GR-Four AWD system, works to provide traction in the current Toyota GR Yaris and upcoming GR high-performance products. It offers three driving modes — Normal, Sport and Track — where power is balanced between the front and rear axles. 

In Normal mode, torque is distributed in a 60:40 ratio, fitting for day-to-day performance; in the Sport setting the ratio is 30:70. The Track mode offers a 50:50 balance. The GR-Four’s electronic control unit controls the drive torque distribution to suit the situation as per data collected, such as speed, acceleration, braking and steering input. 

Subaru Symmetrical AWD 

Unlike most AWDs that wait for a loss of traction before they take action, Subaru’s Symmetrical AWD system continuously redirects extra power to all four wheels at once to ensure consistent power distribution. It also distributes power from left to right and from wheel to wheel, thanks to a centre differential. 

Not all AWD systems in the Subaru range are identical. Cars equipped with continuously variable transmission (CVT) use a Viscous Centre Differential with a 50:50 power distribution and an Active Torque Split system with a 60:40 torque split in all CVTs except the WRX and it works by allowing for some slip. If it detects a loss of traction, it locks the clutch pack and directs power to the axle that needs it. 

Sportier models with a CVT transmission, like the WRX, use a Variable Torque Distribution system that distributes power with a 45:55 ratio to reduce understeer. It uses a centre differential, clutch pack and a transmission control module to send power to the wheel that needs it most. 

Exclusive to the WRX STI is the Driver Controlled Centre Differential system, which uses a planetary system, a mechanical limited-slip differential, and an electronic differential. 

The AWD system in every car is there for one significant reason — improved traction without the need to worry about flicking on and off switches as you’d do in a 4×4 — it automatically performs its magic.  

This system is best suited for providing sportier handling on challenging road conditions, such as mud, sand or snow. So, no, 4×4 won’t make you any quicker around a track.