?Many people think about the AWD system on the Ford Edge the same way they think of the four-wheel-drive (4WD) system on their F-150,? said Ashok Rodrigues, 4WD technical specialist for Ford Motor Company. ?There's been a lot of confusion in the industry as to how manufacturers use the terms 4WD and AWD.? Rodrigues further noted that there are three basic types of AWD/4WD systems, regardless of whether they're based on front-drive or rear-drive vehicles. The three types are part-time, center differential and on-demand.



Rodrigues added that the part-time four-wheel drive. Some enthusiasts call it 4WD. Part-time systems are found on F-150 and Super Duty. Ford F-150 truck parts, for instance, incorporate a simple lock and unlock feature. The function is to lock the front wheels to the rear wheels. The system can be used by pressing a button or flipping a switch on the dash.

?With a part-time system, you will inherently bind up when you go around corners,? said Rodrigues. ?When cornering, the front wheels want to track a wider arc than the rear wheels. Because all four wheels are locked together physically, you simply can't do that with part time. It is an inherent part of the design and is fully intended.?

Center differential system, on one hand, splits the torque that the car engine produces - 40 percent goes to the front wheels and 60 percent to the rear wheels, unlike the previously mentioned system, the wheels of a car with part-time system turn independently at different speeds. Hence, it removes binding when cornering.

On-demand all-wheel drive system drives one axle and then another as road conditions demand. Fusion and Edge' primary drive axle is the front axle while in Explorer it is the rear axle. Ford Explorer auto parts integrate computer controller that monitors engine speed, position of the accelerator pedal, and steering angle to deliver accurate amount of torque as needed.

?What's really impressive about these systems is that they don't just react to slip,? said Rodrigues. ?They usually prevent that slip from occurring in the first place. By predicting slip and preventing it, the driver doesn't feel the vehicle slipping and responding. The operation is seamless.?

2004 Ford Expedition parts also integrate the system to produce a smooth and confident drive feel regardless of the weather condition. Groundbreaking AWD systems do not help with acceleration it just improves traction and handling but will not give more braking power.