1997 Ford Aerostar Owner's Manual - Page 177

Forced Downshifts To gain acceleration in j (Overdrive) or Drive (Overdrive off) when passing another vehicle, push the accelerator to the floor. The transmission will downshift to the appropriate gear: fourth, third, second or first gear. Traction-Lok Rear Axle (If equipped) This axle provides added drive away traction on slippery surfaces, particularly when one or more wheels are on a surface with poor traction. Extended use of other than matching size tires on a Traction-Lok rear axle could result in a permanent reduction in effectiveness. This loss of effectiveness does not affect normal driving and should not be noticeable to the driver. Electronic 4-Wheel Drive (E-4WD) (If equipped) If your vehicle is equipped with the E-4WD option, power is provided to all four wheels whenever you press the accelerator pedal. It improves both handling and traction during difficult driving conditions, adjusting automatically to your driving needs. Because the entire E-4WD system is controlled by a microprocessor, your vehicle is not equipped with the switch or shift lever used with most traditional 4WD vehicles. The microprocessor does all the adjusting for you. 177