From the Sport Trac Press Release: Not sure if it answers everything, but it's a start. (It does say you can turn the stability control off if desired).
Full-featured Control Trac® four-wheel drive delivers automatic torque split, and a transfer case with gear-reducing low range
Sport Trac 4x4 models now feature the advanced Control Trac® four-wheel-drive system. It includes electronic logic, automatic torque transfer, and a two-speed transfer case with a locking center differential.
Unlike competitive systems, Control Trac® operates automatically, and only when additional traction is needed. This increases safety and security without compromising fuel economy or NVH. This makes the new Control Trac system a big advantage for the Sport Trac, according to John Davis, Sport Trac vehicle engineering manager:
“Most of the compact trucks offer a fairly simple, mechanical part-time four-wheel-drive system. These systems require some sort of operator input to engage them. And when four-wheel drive is engaged, most are not suitable for driving on partially dry pavement.
“The Honda Ridgeline offers an automatic torque split, but it is front-wheel biased, meaning power is transferred from the front-wheels back. And it lacks a low-range for heavy-duty use.â€
* Electronic-shift, full-time 4WD optional on SLT and Lariat models with automatic transmissions.
Control Trac® allows a driver to select between three driving modes:
* The 4x4 AUTO (or A4WD) mode provides full power to the rear axle until the rear wheels begin to slip. Then power is automatically proportioned to the front axle as required for increased traction. This mode is appropriate for any driving condition.
* The 4x4 HIGH (4H) mode effectively locks the center differential, providing a constant 50/50 torque split between the front and rear axles. It is intended only for severe winter or off-road conditions, such as deep snow, ice and shallow sand.
* The 4x4 LOW (4L) mode locks the transfer case and engages a torque-multiplying gear set in the transfer case. It is intended only for off-road applications that require extra power, including deep sand, steep grades, and towing a boat trailer out of water.
Also some on the stability control:
Sport Trac’s agile handling and confident braking provide an added measure of safety and security during emergency maneuvers. Contributing to its confident nature is Sport Trac’s standard four-wheel, four-channel antilock braking system (ABS) with electronic brake force distribution (EBD). The ABS controls the front wheels independently and the rear wheels in tandem during heavy braking – to further help the driver maintain control of the vehicle. ABS with EBD employs dynamic proportioning, measuring braking force versus traction and allocating brake pressure to the wheels that have the best grip even before the ABS system kicks in. This helps reduce the braking distance.
Sport Trac’s exemplary braking system is paired with standard Advance Trac® with Roll Stability Control – an exclusive active safety system not offered by any other manufacturer.
This active stability enhancement system offers a significant difference when compared to typical systems. While typical systems are designed to control yaw or spinout only, Ford’s AdvanceTrac ® with Roll Stability Control goes one important step further.
It can enhance the vehicle’s resistance to rolling over.
Most systems use one gyroscopic yaw-rate sensor as they work to control yaw. AdvanceTrac ® with Roll Stability Control utilizes a second gyroscopic roll-rate sensor to determine the vehicle’s body roll angle and roll rate. If this unique roll-rate sensor detects a significant roll angle, the system applies additional countermeasures – such as applying brakes to one or more wheels or reducing engine power – to enhance vehicle rollover resis
