Stability control is an evolution of traction control that bites one or three wheels or even cuts power to send a car in the desired direction. Traction control only limits wheel spin; stability control can manoeuvre a car. Although traction control systems use the same methods as stability control, their capabilities are much less. The only data the traction control ECU obtains about the car is how fast it is going and how fast the wheels are spinning.
It all starts with an Electronic Control Unit (ECU), plus a series of sensors scattered around the car that measure how fast the wheels are spinning, how fast you are going and how far the car is turning around its centre line, plus a number of other variables that can include how far you have turned the steering wheel and even how fast you have taken your foot off the accelerator to step on the brake pedal. Electronic Stability Control (ESC) is an advanced vehicle stability system that works to help the driver maintain control of the vehicle's steering. Moreover, ESC not only keeps the car stable when accelerating, but also prevents skidding when braking. The more severe the loss of traction, the more noticeable the reaction, with a noticeable dive in forward motion while the system sorts it all out for you.
Stability control can also correct for oversteer, when the rear wheels lose grip and the tail of the car starts to slide. There's a good reason why traction and stability control systems are banned in Formula 1; drivers don't have to be as gentle with the throttle, brakes or steering because a computer can react in a split second to ensure maximum grip and stability, better and faster than even a human of Schumacher's level. It is impossible to know how often ESP systems save people from traction loss accidents, but it is fair to say that they probably save someone, somewhere, every day. That's why ECS is a must on any set of off-road wheels you want to put on, as it has total control over the vehicle and its grip on the road.
If you're one of the small percentage of people who take their cars to a race track, chances are you'll turn traction control off as soon as you arrive and leave it off until you leave, with the aim of having less interference and the ability to balance the car at its limit for better lap times and more Clarkson-like lairism. While traction control uses the differential, or rather the active differential to control tyre slip, for stability control, the basic premise is brake pressure and a bunch of other stuff. These seem rather simple parameters, but the operation of the stability control programmes is quite extraordinary. Stability control, or rather Electronic Stability Control (ESC), debuted on the 1990 Mitsubishi Diamante, but it wasn't until the 1995 Mercedes-Benz S600 coupe in the US that Americans tested it, and how advanced it was over traction control.
Electronic Stability Control (ESC) is a system that keeps the vehicle in the direction the driver wants it to go, which is usually on the road and with the rubber down. Speed sensors are what help the traction control system or electronic stability control to find out any slippage or loss of traction, which they then correct in basic and advanced ways. Most vehicles allow only traction control to be switched off, and in some cases it is possible to disable stability control altogether.
