The rivalry between the BMW 7-Series and the Mercedes-Benz S Class to set the benchmark in full-size luxury sedans has long driven each to out-do the other. The latest volley from BMW is the 2013 7-Series, and it's coming with guns blazing.

Powertrains

Chief among the updates are the powertrain changes for the new model year. The 740i and long-wheelbase 740Li get the N55 inline six-cylinder engine with the now-familiar single twin-scroll turbocharger, rated at 315 horsepower and 330 pound-feet of torque. Paired with BMW's eight-speed Steptronic automatic transmission, the powertrain is roughly 20 percent more efficient in EU combined cycle testing. U.S. EPA numbers will be available closer to the car's launch later this summer.

The second-generation ActiveHybrid 7 pairs the new N55 engine found in the 740i with a 55-horsepower electric motor, eight-speed transmission, and lithium-ion battery for a combined output of 349 horsepower and 367 pound-feet of torque. Gas mileage gains of 14 percent in EU testing combine with 5.5-second 0-60 mph times to make this hybrid both fast and efficient. A boost function puts an extra 155 pound-feet of torque on tap for short bursts of acceleration, and the ECO PRO mode helps improve gas mileage in normal driving conditions.

The 750i and 750Li get an upgraded version of the 4.4-liter twin-turbo V-8 engine, now with Valvetronic, BMW's throttle-less intake system, generating 445 horsepower and 480 pound-feet of torque. That's an increase of 45 horsepower and 30 pound-feet of torque over the previous 750i. With power piped through the eight-speed automatic transmission, 0-60 mph times of 4.7 seconds are possible, while saving 25 percent in EU test cycles.

Unchanged for 2013 is the 760i and 760Li's twin-turbo 6.0-liter V-12 engine.

2013 BMW 7-Series

2013 BMW 7-Series

All of the 2013 BMW 7-Series range gets auto start-stop, brake energy regeneration, and ECO PRO mode. Auto start-stop cuts the engine at idle, for instance at a stop light, and restarts it when the driver lets off the brake. Brake energy regeneration captures some of the kinetic energy that would otherwise be lost in braking and stores it for use by the car's auxiliary systems. ECO PRO mode manages powertrain behavior and programming of the heating, air conditioning, heated seats, and exterior mirror heating to maximize efficiency. The ECO PRO mode also enables the 2013 7-Series to engage its new coasting mode, which lets the car coast farther at speeds from 30-100 mph by decoupling the engine from the transmission. In the ActiveHybrid 7, coasting mode completely shuts off the engine to save even more fuel, restarting it when the driver requests acceleration.

For times when efficiency isn't the primary concern, there are Comfort+, Comfort, Sport, and Sport+ modes, moving progressively from relaxed to dynamic, adjusting throttle response, power steering feel, stability control thresholds, damper settings, and more.

Integral Active Steering is available on rear-drive 7-Series models, adding rear-wheel steering to the Active Steering system to improve handling and maneuverability.

Design

While the 2013 7-Series' exterior design isn't revolutionary, it does evolve the familiar shape of the previous model with more modern details and BMW's latest styling cues. A broad chrome grille surround rises into the long hood, with a long, arching cabin and tiered rear end. The front bumper, side skirts, and rear bumper are designed with aerodynamics in mind, including BMW's "air curtain" system which improves airflow around the front wheels.

Adaptive Xenon headlights are standard on 740i and 750i models, with the characteristic Corona light rights and LED daytime running lights. Adaptive LED headlights are available on all 2013 7-Series models and standard on the 760i and 760Li, giving the front end an even more modern look. At the rear, the familiar L-shaped taillights are surrounded by a chrome strip, essentially unchanged from the previous model with the exception of slightly tweaked colors for greater contrast.

2013 BMW 7-Series

2013 BMW 7-Series

Inside the cabin, new front seats are slimmer than the last model's, with new Ivory White and Veneto Beige colors in Dakota or Nappa leather. Individually adjustable rear seats are standard on 760i/Li models, and optional on others. Long-wheelbase models add 5.5 inches of wheelbase for greater rear-seat leg room, and a slight change to the roofline of the long-wheelbase cars adds a half-inch of extra headroom as well.

An optional rear-seat entertainment package adds an iDrive controller and two 9.2-inch screens, cleverly "floated" behind the rear seats rather than integrated into them.

New ambient lighting, more sound insulation, and other small changes to the interior make it a more comfortable, engaging place to travel.

Entertainment And Information

A new navigation system adds 3D elements to the display, thanks to a more powerful 1.3-GHz processor and a dedicated 3D graphics card, improving the overall speed of the system as well. A revised menu system makes using the iDrive controller quicker and easier, while revised navigation displays convey information more clearly.

On the audio front, a new Bang & Olufsen Surround Sound system brings 16 speakers, active digital signal processing, and Dirac Dimensions technology to improve the listening experience. All-aluminum speaker grilles enhances the look of the system, too.

Voice control is also now standard with the new navigation system, including a new voice memo system that allows the driver to compose and send e-mail and text messages by dictation. A suite of voice-controlled editing tools are included to make sure the message looks as it should.

2013 BMW 7-Series

2013 BMW 7-Series

Safety Technology

A new Enhanced Active Cruise Control system builds on the last-generation Active Cruise Control System with Stop & Go to add the ability to brake to a complete stop if the driver doesn't react to stopping traffic in time. The system alerts the driver to the situation along the way, but will ultimately take over if it deems it necessary.

BMW's Active Protection system is also expanded for 2013, gaining Attention Assistant to monitor the driver's behavior and determine if fatigue is starting to impair their ability to drive safely. If the system detects an unsafe level of fatigue, it will suggest a brake by showing a coffee cup symbol on the instrument panel.

BMW Parking Assistant is available to help get the rather large 7-Series parked safely, using ultrasonic sensors to ensure adequate clearance and safe negotiation in tight spaces.

The 2013 BMW 7-Series will arrive on dealer lots in late summer of 2012, with the ActiveHybrid 7 to follow in the fall. Pricing, U.S. EPA gas mileage estimates, and other details on packaging and pricing will be revealed closer to launch.