2011 BMW 5-series: Bavaria's midsize sedan takes cues from bigger 7-series brother

BMW's appetite for controversial design may have waned since the heights of former design boss Chris Bangle's oft-derided flame surfacing stratagem. But it shows no sign of fading completely, as we see in the first official photographs of the new sixth-generation 5-series, which goes on sale in North America by mid-2010.

Codenamed F10, BMW's midsize sedan is restyled and reengineered in a bid to keep it ahead of key rivals such as the recently renewed Mercedes-Benz E-class and the Audi A6.

Although not nearly as arresting as its direct predecessor, the new 5-series has again strayed into controversial territory with an appearance that picks up on the design language first unveiled on the latest 7-series, but with added flourishes that BMW's new design chief, Adrian van Hooydonk, says are aimed at providing added sportiness.

"We've attempted to match elegance and sportiness together in equal measure to give a unique personality. But at the same time, we've been careful not to stray too far from traditional 5-series visual qualities," he says.

The new car appears more solid and substantial than the car it replaces. The overall detailing is impressive, the result of a three-year program wherein BMW kept refining the appearance after the design was frozen in December 2006.

Reflecting the recent trend of BMW models, the dimensions of the 5-series have been stretched. Length grows by 1.7 inches to 192.9 inches and width by 2.5 inches to 73.2 inches, but height drops by a scant 0.1 inch to 57.6 inches as part of an effort to provide a more coupe like profile. The new 5-series rides on a wheelbase that's gone up by 3.1 inches to 116.8 inches and tracks that are up by 1.6 inches to 63 inches at the front and 1.8 inches to 64.1 inches at the rear.

Doing away with move toward hybrid construction, which saw the front end of the old 5-series fashioned completely from aluminum, the new model returns to a full steel unibody. The body is a combination of steel and aluminum--the latter used for the hood, doors and front fenders--and is claimed to be 55 percent stiffer than before. However, the larger footprint means weight has increased by an average 220 pounds model for model.

Despite the larger external dimensions, interior accommodation has not benefited greatly. The rear seat, by way of example, only gains an extra half-inch of knee room. Space has been added to the trunk.

The interior picks up on the layered effect seen in the outgoing 5-series, but it has been redesigned with a more driver-orientated layout. Eight airbags are offered as standard equipment as part of an armada of safety systems.

Under the hood, there's a combination of old and new engines, all sitting on new mountings that--in combination with the longer wheelbase--help move their weight lower and further back in the chassis and provides for a longer hood than before.

The naturally aspirated 4.8-liter V8 in the range-topping 550i has made way for a twin turbocharged 4.4-liter V8 delivering 400 hp. The performance leader of the new 5-series lineup, it is good for 0 to 60 mph in just 5.0 seconds, and top speed is limited to 155 mph.

Positioned beneath it in the initial two-model North American lineup will be the 535i, with a turbocharged 3.0-liter inline six-cylinder delivering 300 hp, helping it to a 0-to-60-mph time of 6.0 seconds. Its top speed also is limited to 155 mph. That lineup will be joined after the launch by the 528i running BMW's classic 3.0-liter inline six-cylinder with 240 hp.

North American buyers will have the choice of a six-speed manual or an optional eight-speed automatic in both the 550i and the 535i. As part of BMW's EfficientDynamics program, they also benefit from a brake-energy-regeneration system and ActiveAero, a package that sees the cooling ducts behind the enlarged kidney grille close during periods of low-end load to help improve overall aerodynamics.

Although it's not official just yet, BMW also plans to add a hybrid to its 5-series ranks. The new model, to be called the ActiveHybrid 5, is planned to make its public debut in concept guise at the Geneva motor show next year before going on sale in early 2011.

Its looks may split opinions, but the new 5-series promises to be a real driver's car. In a bid to make good on development boss Klaus Draeger's aim that the new 5-series should deliver 3-series levels of agility, BMW's engineers have thoroughly reworked the suspension. Out goes the traditional MacPherson-strut-front suspension--a staple of the 5-series since its inception in 1972. It's replaced by a new double-wishbone arrangement similar to that used on the latest 7-series and recently introduced 5-series GT. The rear end retains a multilink arrangement but it as been redesigned with new geometry and pick-up points.

The new car's project leader, Josef Wuerst, says ride quality was high on the list of priorities, and he promises greater compliancy and refinement than the old 5-series. Other new developments include an electro-mechanical steering system and a further-developed dynamic driver-control system that alters the stiffness of the adjustable dampers, throttle response, gear-change characteristics and degree of stability-control interaction.

Finally, the new 5-series will be a real tech fest. Added to the high level of equipment available on the old 5-series--blind-spot warning, land-departure warning, heads-up display and night vision with pedestrian detection--is a new parallel-park assist system, a distance-warning system which uses sensors to provide a top-view image and frontal collision warning that automatically applies the brakes.

By Greg Kable