The 5 Series is an important model for BMW, particularly in North America where it's the brand's second best seller behind the 3 Series. Heading into 2010, BMW has expanded its mid-size line with the new Gran Turismo body style already on sale. However, the volume leader for the 5 Series is the four-door sedan, which officially debuts today. The 2011 model transitions to a new platform architecture shared with the latest 7 Series as well as the upcoming Rolls-Royce Ghost. The 5 Series sedan gets a four-inch shorter wheelbase than its siblings, but at 116.9 inches, it still stretches well past its competition. The new Mercedes-Benz E-Class runs a mere 113.1 inches between its axles and the Cadillac CTS is 113.4 inches.
Since the 5 Series now shares its platform with the 7 Series and GT, the suspension is essentially carried over from the other two with multi-link arrangements at all four corners, dispensing with the struts of the five previous generations. The outgoing E60 5 Series marked the debut of active front steering for BMW with a steering ratio that varied based on vehicle conditions such as speed and lateral acceleration. The new F10 (BMW's internal nomenclature for the latest 5 Series) adds to that electric power steering assist, which should help reduce parasitic power loss and improve efficiency. How it impacts steering feel remains to be seen, although the 7 Series felt quite good for such a large car when we tested it earlier this year.
The F10 also picks up features like optional active rear-wheel steering, which countersteers the rear wheels for a tighter turning circle while using in-phase steering at speed for extra stability. Other options include an adaptive damping system and active roll control to further minimize lean during cornering.
Inside, the new 5 Series also picks up themes from the GT and 7 Series with a return to an instrument panel layout where the center stack is tilted toward the driver for improved ergonomics. While BMW gave the Gran Turismo an elevated seating position for that "command view," the 5 Series retains a lower position more typical of sedans. Barely a year after introducing its third generation of iDrive in the 3 Series and 7 Series, the new 5 Series gets what BMW is describing as generation four. It's not clear at this point how much better it is, but hopefully the system will have expanded voice controls to get deeper into the menus without having to use its control knob. All models get an LCD display in the dash to display audio and climate control information, while cars without the navigation system get a seven-inch display and those with get the gorgeous 10.2-inch panel from the 7 Series.
Given that BMW's middle name is Motoren, the heart of any Bimmer resides under the hood. In this case the U.S. version of the F10 5 Series will launch with two turbocharged engines. The 550i sedan gets the same marvelous 400-hp twin-turbocharged, direct-injected reverse flow V8 found in the X6, 750i and 550i Gran Turismo. Below that is a 300-hp turbocharged inline-six in the 535i.
However, the latter engine is not a carryover from the current 535i and 335i. The existing turbocharged inline six-cylinder uses two turbochargers feeding the front and rear halves of the engine and retains a throttle plate. This new engine keeps the same displacement and maximum output of 300 hp and 300 pound-feet, but uses only a single twin-scroll turbocharger and dispenses with the throttle in favor of the Valvetronic variable lift system to manage airflow into the engine. That makes it the first BMW turbo six with the Valvetronic system.
Both engines are paired with the same new eight-speed automatic transmission found in the Gran Turismo and the ActiveHybrid 7. The six-cylinder model is also available with a six-speed manual gearbox, a unique offering among its competitors in the U.S. market. Later in 2010, BMW will also add a normally aspirated version of the six with 240 hp.
The new 5 Series will be the first U.S.-market BMW other than the company's new hybrids to get brake energy regeneration. Like the new electric power steering, this regen braking system uses a special heavy duty glass-mat battery in combination with an intelligently controlled alternator. While a normal alternator is being driven continuously, this unit only charges the battery when the car is decelerating to avoid adding any load to the engine.
Of course, the most obvious difference for the new 5 is its styling. Over the past decade, BMW has had some very controversial exercises in design, including the current E60 5 Series. The new 7 Series is considered one of the most successful BMW designs in many years and the 5 Series picks up that mantle. Unlike the the somewhat awkward looking Gran Turismo, the sedan keeps a lower profile more akin to the 4th generation E39 5 Series. The nose is also more upright like the 7 Series and GT compared to the slope back shape of the E60.
The bodywork picks up some of the surface queues seen on its siblings including a pair of prominent creases on its flanks at the rocker panel and just below the belt line. Speaking of the lower edge of the side glass, this wouldn't be a BMW without the Hofmeister Kink, but this time the radius has been reduced. The overall effect is less avant garde and more muscular than the E60, and most observers will likely find it more pleasing to the eye.
The new 5 Series sedan will certainly spawn a new high-performance M5 version at some stage, although BMW is not giving any details at this time. In all likelihood, the days of the 5.0-liter V10 are over and the M5 will get a version of the 550-hp twin-turbo V8 found in the X5 M and X6 M. On the more efficient side, we may get a diesel 535d at some point and almost assuredly a hybrid, probably with the mild hybrid system used in the ActiveHybrid 7. What we probably won't see again in the U.S. is the slow-selling Touring station wagon, which doesn't really have much reason to exist alongside the Gran Turismo.
