SH-AWD is an active all-wheel drive system that has been installed on Acura and Honda cars since 2004. It works together with traction control, stability control, and other systems. It improves the vehicle’s off-road capability, dynamics, and handling.
How it works
The key advantage of SH-AWD is its constant adjustment of the engine torque according to the road conditions. Most of the torque is transmitted to the axle with better traction, allowing the engine power to be used with maximum efficiency.
A multi-plate clutch with electronic control functions as the centre differential. Its degree of lock-up affects the amount of torque supplied to each axle. The front differential is open.
The rear drive unit consists of two planetary gears with individual electromagnetic clutches. This allows 100% of the torque transmitted to the rear axle to be distributed to the wheel with better traction. In some models the rear drive unit features an acceleration device to increase the wheels’ rotational speed.
Some premium-class cars are equipped with an SH-AWD hybrid drive. In this design, the engine torque is supplied to the front axle only. The rear wheels are driven by two independent electric motors.
Technical characteristics of SH-AWD
| Type | Centre differential | Rear axle differential | Production start | Models equipped with this drive type |
| Full-time AWD | Multi-plate clutch. The torque can be distributed between the axles in a 90:10 or 70:30 ratio depending on the traction of the wheels. | Two hypoid gears with electromagnetic clutches. | 2004 | Honda Legend KB1, KB2; Acura RDX; MDX YD2, YD3; TL UC; ZDX; TLX. |
| Full-time AWD | With an acceleration device | 2009 | Acura RL KB1, KB2. | |
| Hybrid AWD | The SH-AWD control unit is responsible for torque distribution. | Not installed. Each wheel is driven by an individual electric motor. The Twin Motor Unit (TMU) controls the torque supplied to the rear axle. | 2011 | Acura RLX; NSX |
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