Introduction to Stability Control

Electronic stability control, often referred to as antiskid, goes by many names: GM calls it StabiliTrac, Ford dubs it AdvanceTrac, and Chrysler names it Electronic Stability Program (ESP). Other names include Vehicle Dynamics Control (Subaru), Dynamic Stability Control (Volvo), Vehicle Stability Assist (Honda), and Vehicle Stability Control (Toyota). A stability control system uses several sensors to detect a loss of traction in your vehicle, then works with the antilock brake system to apply individual brakes to help keep the vehicle on its intended path. In some cases, an antiskid system also reduces engine power.


photo courtesy of Ford
Ford's stability control is called Advance Trac. Like other stability-control systems it works to keep a vehicle on its intended path.

How Stability Control Works

Much like antilock brakes work to allow the driver to steer while braking on slippery surfaces, stability control works to help the vehicle stay on its driver-intended path in turns. Sometimes a driver will enter a curve too quickly and exceed the tire's ability to hold the road through the turn. When this happens, the vehicle begins to spin or skid. Stability control pulsates the brakes of individual wheels to help "rotate" the vehicle to the driver's intended path.


photo courtesy of Ford
Stability-control systems utilize several sensors and a computer to determine the driver-intended path for a vehicle. The system will attempt to prevent a skid by applying individual wheel brakes.

So what does this mean to the driver? Well, if you approach a corner too rapidly and your vehicle begins to plow straight ahead, an antiskid system will detect that the vehicle is not on its intended path and intervene by applying the inside brakes. This will rotate the vehicle through the turn and, hopefully, save you from going off the road. Antiskid systems can't defy the laws of physics, so they won't help you take a 90-degree turn at 100 mph, but they can be quite helpful in most situations. Antiskid systems are available on many cars, trucks, and SUVs, but they are usually optional. Stability control is an important safety feature on today's vehicles, so make sure the vehicle you are considering has it.

Roll Stability Control
Roll stability control works very much like an antiskid system, but uses additional sensors to detect an impending rollover. It then activates the antiskid system in a manner to prevent a rollover. Roll stability control systems work on flat pavement; they can't prevent rollovers caused by hitting a curb or sliding into a ditch. Also, roll stability control should not be confused with what may be called rollover protection; these systems deploy curtain side airbags when detecting an impending tip. Volvo, Ford, Mercury, Lincoln, Land Rover, and Jeep have roll stability control systems.