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Symmetrical All Wheel Drive

Stephen Rampur Mar 21, 2020
In the automobile world, Symmetrical All Wheel Drive generally relates to the AWD system incorporated by Subaru in all their cars and SUVs...
Four wheel drive and all wheel drive has become a common technology in cars and SUVs manufactured today. This aids in better traction on snowy and slippery roads by changing the amount of engine power to all wheels separately.
Note that Four Wheel Drive (4WD) and All Wheel Drive (AWD) are technically two different things, although used interchangeably for marketing and advertising purposes in layman terms.
The world of AWD is ever evolving with new AWD variations coming up in latest cars. One such technological innovation is the Symmetrical All Wheel Drive offered by the off-road specialist 'Subaru'. Note that the brand's system is altogether a different 4x4 system.

Subaru Symmetrical All Wheel Drive

This AWD system controls engine power to all wheels on an individual basis, which really helps in avoiding an oversteer or understeer. Unlike front- or rear-wheel based 4WD systems, this AWD powers all wheels at all times, right from the start of the drive. This leads to utmost traction and control to preclude accidents.

Engine Placement

The system is one of a kind drive setup. It goes right just as it is stated. Most of the components in this AWD system are set symmetrically. One of the most important part of this system is the SUBARU BOXER engine. The engine is longitudinally mounted in the system as one single piece in line with the driveshaft, and not in parts coming together to make a complete engine.
Moreover, it is also placed at a lower level than engines in other cars. In this flat-engine configuration, the pistons which are situated right opposite to each other balance out vibrations generated. This engine system is one step ahead of the traditional in-line or V-type engine types. Bulky parts such as the transmission, transfer case, differential, and propeller shaft are set up at the back in the system. So, the center of gravity becomes the center of the wheelbase, and not somewhere in the front.
Two sides of the drivetrain face each other, which contribute to a substantially reduced center of gravity. This is what allows the vehicle to remain well-balanced on the road. So, because of the well-distributed balance in these AWD cars, even sudden maneuvers will not make the vehicle go out of control. Less components on the assembly, means less would be the wear and tear. Owing to a reduced weight, the vehicle would have a good fuel economy. The power also gets a boost due to an uninterrupted power from the engine.

Direct Power to Wheels

Another advantage of this type of assembly is that due to the placement of the engine, the power flows in a straight line. This is right opposite to the functioning of other AWD systems which have to position additional parts to direct power from the engine to axles. This requires the power from the engine to go through 90-degree angles, before reaching the axles.
In the symmetrical AWD system, the power is transferred straight from the engine-transmission-transfer case, finally to the driveshafts. Therefore, the axles are run by true power that has gone through least interference. The drive system also changes the amount of power to each of the wheels, as per the road condition. The individual power transmission is done by a center Limited Slip Differential (LSD).
Subaru has always been a prominent entity in the World Rally Championship (WRC) races. The performance of cars is largely benefited by the mentioned AWD system from the company.
Note that all cars and SUVs from the Japanese automaker are embedded with the Symmetrical All Wheel Drive, which no other major brand does. Since Subaru started its research and development of AWD systems in 1972, its drive and traction can certainly be trusted.