Vehicle Overview
BMW redesigned its midsize 5 Series for 2004 by making it slightly larger and giving it a fresh exterior look. Backseat space and trunk capacity increased and a new all-aluminum front-end structure helped reduce the car's weight. A simplified version of BMW's iDrive control system, adapted from the larger 7 Series, was installed.

For 2007, an auxiliary audio input and a tire pressure monitoring system are included. New options include HD Radio, which improves FM and AM signal quality, and BMW Night Vision, which uses a thermal-imaging camera to create an image of what's ahead on the iDrive system's screen. Real-time traffic information is included in 550s that have a navigation system.

In addition to the 550, inline-six-cylinder-powered 525 and 530 models are offered. They are covered separately in the Research section. Both the 525 and 530 can have all-wheel drive instead of rear-wheel drive.

Short overhangs and what BMW calls "lean-forward dynamics" highlight the 550's design. A prominent twin-kidney grille continues the BMW tradition. The grille is flanked by quad headlights inside luminous rings and beneath clear covers. The 5 Series bodies incorporate BMW's traditional reverse kink at the rear door windows, and the contemporary rear end features a high trunk lid. An aluminum suspension is installed.

Adaptive xenon headlights, adaptive brake lights, rain-sensing wipers, and automatic-dimming inside and outside mirrors are standard. Standard wheels measure 17 inches in diameter, but 18-inch run-flat performance tires — which are wider at the rear — are included in the Sport Package.

Up to five people can fit inside the 550 sedan. Leather upholstery and Dark Poplar wood trim are standard. Maple Anthracite interior trim can be substituted. Front occupants get 10-way power seat adjustment with a driver memory feature. Heated front seats are optional.

The tachometer incorporates a variable warning segment that activates at a lower rpm when the engine is cold. A 10-speaker Radio Data System CD stereo with twin subwoofers is standard, and Sirius Satellite Radio is optional.

A simplified version of BMW's iDrive control system uses a 6.5-inch display screen. Radar-based Active Cruise Control is optional, while front and rear Park Distance Control is standard.

Under the Hood
The 550's 4.8-liter V-8 develops 360 hp and 360 pounds-feet of torque. A six-speed manual is standard. A six-speed Steptronic automatic or a six-speed Sequential Manual Gearbox is available. Shifted electrohydraulically, the sequential manual incorporates an automatic clutch. Gear changes can be selected using a console-mounted lever or paddles on the steering wheel.

Antilock brakes, Dynamic Stability Control, side-impact airbags for the front seats and side curtain airbags are standard. Rear-seat side-impact airbags and active front head restraints are optional.