The performance of ABS will vary from car to car, and from manufacturer to manufacturer. Although the principle behind how ABS works stays the same. But even ABS can loose it’s effectiveness under certain situations. The ABS system equipped on my Expedition Limited works flawlessly, but then again, the ABS is not left alone to fend for itself. The Expedition uses four systems to bring it to a stop; ABS, AdvanceTrac with RSC (Traction Control System) and Electronic Brake Force Distribution (the Impala should have BFD if I’m not mistaken) All four systems are linked together to work as one. The Expedition Limited will take control of itself (but not steering) during a high-speed emergency maneuver. It is weird to have a vehicle all-but remove you from driving.