Rockport, Maine - Safety first, big guy. Your uncle's advice as he slips you a package of Trojans before you head off for a blind date also could be Volvo's admonition as it brings out its new electronic all-wheel-drive system. That system made its debut on the tantalizing Performance Concept Car, a 300-horsepower, electric-blue bombshell that was revealed at the 2000 Paris auto show.
But before it's touted as a performance enhancer, the new all-wheel-drive system appears first as a mere traction aid on the not-exactly-sporty mid-level S60 sedan. Here it works with a 197-hp, 2.4-liter turbo five and a five-speed manu-matic transmission.
The new electronically controlled all-wheel-drive system differs from the passive system in the current Cross Country in that instead of using a viscous coupling to engage drive to the rear wheels, a computer-controlled multi-plate clutch handles that task. Connected to the car's Multiplex wiring system, the electronically engaged rear axle works in tandem with the engine- and brake-control modules. The speed of the vehicle is taken into account so that rear-wheel drive doesn't intrude when it's not really needed, such as during parking maneuvers. The next step, which won't be ready for another year, is to link the system with stability control for additional handling advantages.
In practice, the all-wheel-drive mode is invisible to the driver, except when you realize that understeer has been neutralized on slick surfaces, and any annoying torque steer is absent. We churned up some earth on an unpaved slalom course, and, while the steering wheel felt rather lifeless under rigorous whipsawing--seemingly controlling a rudder instead of the front wheels--the S60 kept plodding along, keeping its front end ahead of its rear.... Read full article