The new benchmark: whether you're tearing down the styling or tearing down the car, BMW's 5 Series still sets the standard

Automotive Industries,  Oct, 2003  by Gary Witzenburg

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BMW's latest (version 8.0) Dynamic Stability Control (DSC) is standard across the board. Briefly pushing its console-mounted switch activates Dynamic Traction Control (DTC), which de-activates "engine intervention" leaving only the individual wheel brakes to control wheelspin below 43 mph in specific low-traction conditions. A longer push of the same button de-activates all DSC functions except anti-lock braking.

Wheals, tires and brakes am up-sized and upgraded throughout. Wheals range from standard 16 x 7 in. on the 525i to 18 x 8 front and 18 x 9 rear on the Sport Package 545i. Corresponding tires range from 225/55R-16 V-rated all-season to 245/40R-18 and 275/35R-18 W-rated run-flat performance. A Flat Tire Monitor (FTM)--which uses the DSC sensors to monitor and compare rotational wheel speeds--is standard on all models, while run-flat tires (which maintain their shape and stability for a considerable distance following a loss of pressure) am a feature of all sport packages.

BMW's adaptive brakelights, which debuted on the new 7 Series and have spread to the Z4, X5 and 3 Series coupes and convertibles, increase their illuminated area under hard braking to warn following drivers of emergency stops. Adaptive Xenon headlamps (optional on 525i and 530i standard on 545i) help drivers see around corners by steering along with the front wheels, swiveled by small servo-motors guided by ,an electronic control system. The headlamps also auto-level to compensate for load and transitory" braking and acceleration.

The "evolved" iDrive is a simplified version of the all-powerful, oft-enfuriating electronic systems control that debuted to mixed reviews in the '027 Series The noble idea is to control climate, entertainment, communication and (optional) navigation systems through a single large knob on the center console. BMW's overly complex and sometimes counterintuitive execution has had 7-Series owners reading themselves to sleep with their manuals. The 5 Series simplifies it somewhat and adds a single hard button to recall the main menu. (Audi does it far better with several well-marked hard buttons to access specific functions.)

Both standard and optional premium sound systems are enhanced and integrated with the standard (OnStar-like) BMW Assist and option-navigation, phone and Sirius Satellite Radio systems, all receiving signals through a single shark-in roof antenna. Safety features include two-stage front air bags, front and rear Head-Protection Systems and (with optional 20-way front seats) active head restraints, all coordinated by an Intelligent Safety and Information System (ISIS), which uses 10 sensors in tailor system responses to accident circumstances.

One very interesting world first technology is Active Steering, a feature of the optional Sport Package available on ,all models, which electro-mechanically varies the steering ratio based on vehicle speed and dynamic conditions to enhance response and stability. The ratio varies from a very quick 10:1 for parking, U-turns and sharp low-speed corners to a leisurely 20:1 for highway cruising. (We tried it through a tight slalom and other maneuvers, and it works exceptionally well See AI Sept. '03 "Bosch-ZF Active Steering" for technical details.) Active Roll Stabilization, also part of the Sport Package, replaces the conventional front and rear anti-roll bars with active bars twisted by hydraulic actuators for "amazingly flat" cornering.