Torque vectoring. That is, the mechanical act of varying the amount of torque sent to each wheel — left to right in two-wheel-drive cars and also front to back in AWD — to improve traction and maximize a car's cornering ability. Did I say mechanical? Silly me. I also mean electronic.
Many modern cars these days come with mechanical torque-vectoring systems. The most highly advanced can divvy up torque side to side and front to back with astonishing speed and accuracy, with a computer sorting through a multitude of inputs, from wheel speed and steering angle to yaw rate and lateral and longitudinal G forces.
The most complex torque-vectoring systems, like Audi's ZF system and Acura's Super Handling All-Wheel Drive, can distribute torque between the front and rear axles as needed, and also use specialized, computer-controlled differential units that produce braking torque on the inside wheel while at the same time generating driving torque on the outside wheel. They're seriously mind-blowing electromechanical devices to wrap your head around, if you happen to have that inclination.
But as Chris Harris will show you on this week's Chris Harris on Cars, the Mercedes SLS AMG Electric Drive can do the same thing without byzantine mechanical systems. It does its torque vectoring with an electric motor at each corner. Sensors and software tell those motors what to do — when to add torque and when to drag — and they do it instantly and without crazy clockworks with torque accelerators, electromagnetic clutches and solenoids up the yin-yang.
The potential for flexibility, by way of an almost infinite degree of fine-tuning the left-to-right torque split, is one of the unsung benefits of an electric car. Of course, it has to be a car with four motors and a dizzyingly complex array of gadgetry to make it work. And by "it," I mean managing the Merc's oodles of torque like angels dancing on the head of a pin.
But if you're paying a half-mill for an electric supercar, you probably expect you'll get that stuff standard, right?