With new engines and more power for 2008, BMW's numeric nomenclature for six-cylinder 5 Series models has changed. But the model line hasn't really changed at all. There are two six-cylinder engines, a V8, and an ultra-high performance V10, manual and automatic transmissions and optional all-wheel drive. The 5 Series Sports Wagon is offered only with the more powerful six-cylinder and all-wheel drive.

The least expensive 5 Series is now the 528i ($44,300), powered by BMW's high-tech magnesium alloy 3.0-liter inline 6 generating 230 horsepower, or 15 more than the previous 525i. With all 5 Series models, buyers can now choose either a six-speed manual or six-speed automatic transmission for the same price. The 528xi ($46,500) adds BMWs x-Drive automatic all-wheel drive system.

The 528s come with leatherette upholstery, dual-zone automatic climate control with active micro-filtration, an AM/FM/CD stereo with 10 speakers, 17-inch alloy wheels, four power outlets and a rechargeable flashlight in the glovebox.

The newly designated 535i ($49,400) and 535xi ($51,600) get a 300-hp, twin-turbocharged 3.0-liter six launched in 2007 3 Series cars. That's an increase of 45 horsepower over the former 530i. The 535xi Sports Wagon ($54,000) has x-Drive all-wheel drive. All 535s add xenon adaptive headlights.

The most popular option for the six-cylinder models is the Premium Package ($2,300 for 528i, $2,100 for 535i), which adds Dakota leather upholstery, a universal garage door opener and the swanky interior lighting package with ambient light, auto-dimming and outside approach lighting.

Those items come standard on the 550i ($58,500), which is powered by a 360-hp, 4.8-liter V8. The 550i also comes with Park Distance Control parking assist.

For 2008, the 535s and the 550i can be equipped with a Sport Automatic ($500) transmission, which adds paddle shift bars on the steering wheel and shifts more crisply in manual mode. BMW's Sequential Manual Gearbox, which works like a manual without a clutch pedal, is no longer offered on any 5 Series except the ultra-high performance M5.

The M5 ($82,900) sits atop the 5 Series lineup. It's powered by a hand-built 500-hp 5.0-liter V10, with suspension and brakes enhanced to match all the power, offered with either a six-speed full manual or a seven-speed SMG clutch-less manual gearbox.

Two big ticket options have been added for 2008. BMW's Lane Departure Warning system ($500) is camera based, and notifies the driver via mild steering-wheel vibration of any movement that might indicate an inadvertent lane change. The new Stop and Go feature for Active Cruise Control ($2,400) is space age. Like the previous system, it uses radar to keep the 5 Series from moving to close to a car ahead, without driver intervention. Yet the new Stop and Go system works even in heavy traffic, accommodating speeds all the way down to a complete stop, and resuming to the set speed from 0 mph.

Other option groups include: the Cold Weather Package ($750), with heated front seats, heated steering wheel and heated, high-pressure headlight washers; the Sport Package ($2,800 for six-cylinder models, $1,300 for all-wheel drive and $4,600 the 550i), with BMWs Active Steering and Active Body Control systems, larger wheels with performance tires, more potent brakes and sport seats; and Logic7 audio ($1,200) with six-CD changer.

Stand-alone options include a navigation system ($1,900), a folding rear seat ($475), Sirius satellite radio ($595), and a new auxiliary iPod/USB jack ($400). HD Radio ($500) delivers enhanced digital audio quality, with FM reception that compares to CD quality and AM reception comparable to analog FM. BMW's head-up display, or HUD ($1,200), projects speed and other data on the windshield, while Night Vision ($2,200) uses a thermal-imaging camera that monitors the road ahead and displays images on the navigation screen before they might be visible to the naked eye.

Safety features nearly cover the gamut. Passive safety equipment includes front airbags with dual threshold deployment, front-passenger side airbags and curtain-style head-protection airbags for all outboard passengers. All 5 Series models come with antilock brakes with Dynamic Brake Control auto-proportioning, Dynamic Traction Control, Dynamic Stability Control anti-skid electronics, seatbelt pretensioners and force limiters. The standard BMW Assist communication package includes automatic collision notification, an SOS button, roadside assistance and locater service.

Beyond the Lane Departure Warning System, optional safety features include rear passenger side-impact airbags ($385).