Torque Vectoring

Torque vectoring is a chassis technology that actively varies how much driving force, or in some implementations braking force, is delivered to each individual wheel in order to shape the car's behaviour through a corner. Rather than treating the driven wheels as a pair that must receive equal effort, a torque-vectoring system can favour one wheel over another, using that asymmetry to turn the car more keenly, hold a tighter line and resist the loss of grip. Its purpose is to make a vehicle both more agile and more stable, two goals that are usually in tension.

The physics rests on the fact that the outer wheels travel a longer path than the inner wheels in a turn, and that applying more drive to the outer wheel generates a yaw moment that helps rotate the car into the bend. By sending extra torque to the outside rear wheel, a torque-vectoring system effectively pushes the back of the car around the corner, countering the natural tendency of many cars to understeer, where the front washes wide and the car runs straighter than the driver intends. The result is sharper turn-in and a more neutral, responsive feel without the driver having to do anything.

There are several ways to achieve this. The simplest, often called brake-based or brake torque vectoring, uses the existing stability-control hardware to nip the brake on the inner wheel, which biases drive towards the outer wheel through an open differential; it is inexpensive but dissipates energy as heat. More sophisticated systems use an active differential containing clutches or an additional gear set that can mechanically apportion torque between the left and right wheels on demand. The most capable solution appears on electric and hybrid vehicles fitted with a separate motor for each wheel or axle, where the controller can meter torque to every wheel independently and instantaneously, giving the finest and fastest control of all.

The benefits for the driver are tangible. Cornering feels crisper and more precise, the car settles more confidently under power, and traction improves because drive is directed to the wheel best able to use it, reducing wasteful wheelspin on the unloaded inner wheel. On slippery or split-grip surfaces the same ability to vary torque side to side helps the car put its power down cleanly and maintain a steady course, blending performance with safety.

Torque vectoring is closely related to, but more capable than, a limited-slip differential, which can only resist a speed difference between the two wheels rather than actively command a torque split. It works alongside the ordinary differential and stability-control systems, and on all-wheel-drive cars it can operate front to rear as well as side to side. Honda's earlier active torque-transfer systems were forerunners of the idea, and today torque vectoring is a key tool by which manufacturers give cars sharper handling without sacrificing the stability and traction that everyday driving demands.