ALL-WHEEL DRIVE adds brains to traction
Ford’s all-wheel drive (AWD) system is coming on the 2007 Ford Fusion, Lincoln MKZ, Mercury Milan, Ford Edge and Lincoln MKX.
"Literally in the blink of an eye, the system gauges the conditions of the vehicle and applies power to the most appropriate wheels to maintain optimal traction," said Robert Parker, Ford car marketing manager. "The system monitors the vehicle’s condition 100 times a second. At highway speeds, the system can react within 1/8 of a turn of the wheel."
Unlike four-wheel drive (4WD) which depends upon the driver to shift into 4WD mode, an all-wheel drive system continuously monitor’s the vehicle’s condition and takes actions independently. To the driver, the shift of power from wheel to wheel is seamless.
The all-wheel drive system monitors what’s happening with the wheels on the road along with the driver’s inputs such as turns of the steering wheel and the pressure applied to the accelerator. Not only is power and traction varied on the wheels, the system can also change the engine speed if it’s too fast for the situation, for example if the driver panics and hits the accelerator when the situation calls for less speed.
"A major advantage of all wheel drive is the flexibility to shift power or apply braking to any wheel," Parker said. "In the past we could either shift power from back to front or from front to rear. With advances in AWD technology, we can shift power to the exact wheel or wheels with the best traction."
In the AWD technology destined for the 2007 models, a vehicle like the Fusion or MXZ is typically front-wheel drive. Power goes to the front wheels, which in turn pull the vehicle along. Because the engine rests over the front of the vehicle, the weight provides greater traction to the wheels both pulling and steering the car.
If, however, the system senses a loss of traction it shifts power to any or all of the wheels. The obvious benefit occurs under slippery road conditions, but the all-wheel drive system provides optimal traction under a number of less obvious situations.
For example, a common problem with front-wheel drive vehicles is understeer, typically seen in cornering. If a front-wheel drive vehicle accelerates into a turn, too much weight can be shifted to the rear, causing loss of traction in the front wheels. The front of the vehicle can go towards the outside of the turn when the driver is aiming to turn the car sharply. All-wheel drive automatically compensates either by adjusting the power to the wheels, altering engine speed or both.
Ford is becoming a leader in AWD technology, expecting to sell approximately 500,000 AWD-equipped vehicles annually, beginning in 2007. And while the technology is the current hot trend, the motivation behind its introduction in the company’s vehicles is the same old story at Ford.