Torque Vectoring AWD

Standard AWD distributes torque front-to-rear. Torque vectoring takes it further — it actively varies torque side-to-side on the rear axle. In a corner, the system can send more torque to the outside rear wheel, which pushes the rear of the vehicle into the turn and makes the car feel sharper and more agile. It is like having a throttle for each rear wheel independently.

Most torque vectoring systems use twin clutch packs in the rear differential — one for each axle shaft. By engaging one clutch more than the other, the system speeds up one wheel relative to the other through a gear set, which transfers torque to that wheel. Honda's SH-AWD (Super Handling All-Wheel Drive) is one of the best-known examples. It uses a bevel gear arrangement and twin clutch packs to overdrive the outside rear wheel in a turn by up to 5 percent. The result is a noticeable rotation into the corner that makes a heavy SUV feel lighter on its feet.

Electric vehicles with dual motors or individual wheel motors can do torque vectoring through software alone. Each motor can produce different amounts of torque independently. Tesla, Rivian, and other EV manufacturers use this approach — no clutch packs, no gear sets, just different torque commands to each motor. This is simpler, faster, and more precise than mechanical torque vectoring.

Honda and Acura SH-AWD is used on the TLX, MDX, and RDX. Ford used a twin-clutch rear drive unit on the Focus RS. Audi offers a sport rear differential on RS models that provides torque vectoring. BMW M xDrive can vector torque to some degree. On the EV side, Tesla, Rivian (with four motors), and Hyundai/Kia (on the Ioniq 5 N) use electronic torque vectoring.

Clutch-based torque vectoring systems require specific gear oil for the clutch packs — usually a limited-slip additive or a manufacturer-specific fluid. The clutch packs wear over time and can develop shudder, similar to a limited-slip differential. Fluid service at the manufacturer-recommended interval is important. On the Honda SH-AWD, the rear differential fluid service is often overlooked and should be done every 30,000 miles. Electrical failures in the clutch actuator or speed sensors will disable the torque vectoring function — the system defaults to a standard open differential or basic AWD split.