The system can sense an incipient sideways skid, selectively apply one or more brakes, and depending on the design, reduce engine power to keep a vehicle on its intended path.

Stability control is now available for about 30 SUVs. We highly recommend it. But having tested more than a dozen SUVs with such systems, we’ve seen that it’s not a cure-all for inherent handling problems. Its effectiveness depends on how it is programmed and integrated with the vehicle.

For example, stability control improved emergency handling for the Mitsubishi Montero in tests that we performed about two years apart. The model we tested in 2001, which did not have stability control, was rated “Not Acceptable.” In 2003, a model that had stability control was rated as poor in our tests. In this month’s testing, the BMW X5 3.0i was rated poor in emergency handling despite its stability-control system. And the systems on the Acura MDX and Subaru Outback VDC do not intervene as effectively as we’d like. Vehicles with better-integrated systems include the Audi Allroad, Infiniti FX, Lexus RX330, Nissan Murano, most Toyota SUVs, and the Volvo XC90.