Word: carly
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Dates: during 1980-1989
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What is four-wheel steering? The concept is simple. Rather than controlling a car solely by the angle at which the front tires meet the road -- the method used by wheeled vehicles since the horse-drawn carriage -- four-wheel steering turns the wheels simultaneously at both ends of the car. The idea is intuitively appealing to any city driver who has ever pulled up to a too-short parking space and wished he could point all four tires toward the curb and crab right...
...easy. For starters, the rear wheels of a four-wheel-steer car do not always turn in tandem with the front wheels. Depending on the speed of the car, the rear wheels may turn in the same direction (same-side steering) as the front wheels, or in the opposite direction (countersteering). Most of the new four-wheel-steer autos are capable of both countersteering and same-side steering. In sharp, slow-speed turns, countersteering can shave a full yard off a standard sedan's turning radius. At high speeds, however, countersteering can make a car dangerously unstable, while same-side...
...difference comes from the dynamics of high-speed motoring. When a driver traveling at highway speeds turns the wheel of a conventional, two-wheel steering car, the front tires immediately begin to pivot and the car's forward momentum generates a powerful sideways or cornering force at the front axle. The rear tires, however, have to wait until the car has actually started its turn before they begin to generate a corresponding force at the rear axle. That is why a car with two-wheel steering fishtails during lane changes, the back end is trying to catch...
...four-wheel-steer car, this high-speed sway can be damped or even eliminated through the use of same-side steering. When the rear wheels are turned at the same time and in the same direction as the front wheels, the back end turns with the front, and the cornering forces occur at both axles simultaneously. The car slides smoothly to the side without sway or fishtail...
Experts differ on four-wheel steering's potential. Jerry Rivard, vice president of Bendix Electronics, a major auto supplier, calls it a "dramatic jump in technology" and predicts that it will be standard equipment on cars of the future. Ron Glantz, an auto analyst at Montgomery Securities, feels otherwise. "Other than parking," he says, "the only benefit is on gravel roads at speeds over 70 m.p.h." In Japan, where the technology was first marketed more than two years ago, car buyers seem favorably impressed. Nissan reports that 40% of the Japanese who pick the flashy Skyline model ask for four...