Taking a closer look into Acura’s SH-AWD
Handling is one feature Acura is proud, especially now that they feature Super Handling All Wheel Drive or commonly called SH-AWD in their vehicles. Honda Motor Company describes it as “A world’s first, the SH-AWD system combines front-rear torque distribution control with independently regulated torque distribution to the left and right rear wheels to freely distribute the optimum amount of torque to all four wheels in accordance with driving conditions”. It was first developed for the 1997 Honda Prelude Type SH.
Components of the SH-AWD system were developed by BorgWarner. It primarily is a set of clutch packs in a T shaped differential at the rear of the vehicle. There is no center differential, rather, the vehicle’s have transverse mounted engine’s with power take off units going to the T shaped rear differential/clutch packs. The three clutch packs can engage for the right rear wheel, the left rear wheel, or near the base of the T.
SH-AWD tackles understeer, or the plowing of the front tires, during hard cornering. Acura’s SH-AWD is primarily front-wheel drive, and during regular driving torque will split more toward the front wheels, maintaining the feel of a front-wheel-drive vehicle. On the Acura RL sedan, the default torque split is 70 percent to the front wheels and 30 percent to the rears, but torque split will differ depending on the vehicle; SH-AWD is also available on the MDX and RDX.
Automotive critics say that one of the unique features of Acura’s SH-AWD is its ability to make the outer rear wheel spin faster than the front wheels in hard cornering on dry roads, which is called overdriving the wheel. Overdriving the outer rear wheel helps reduce understeer, and up to 100 percent of the engine’s torque can be sent to that outer real wheel in the right circumstance.