BMW officially reveals the new 2014 M6 Gran Coupe ahead of its launch next summer. Neatly filling a void between the M6 Coupe and M5, the M6 Gran Coupe is BMW’s response to Audi’s S7 and Mercedes-Benz’s CLS63. Here is a four-door gran turismo packed with all the power and luxury needed — featuring a twin-turbocharged 4.4-liter V-8 engine rated at 560 horsepower and 500 pound-feet of torque. Power is first sent to a seven-speed dual-clutch transmission and onto a unique limited-slip Active M Differential before reaching the rear wheels. On top of continuously adjusting locking force, the Active M Differential also analyzes accelerator position, wheel rotational speed and yaw rate to counter any traction loss by varying the degree of axle lock. The engine also merits mention — it produces about 10 percent more output and 30 percent more torque than the old M V-10, delivering its peak output from 1,500 all the way up to 5,750 rpm. Other improvements include aluminum-intensive suspension, reinforced chassis mountings, electronically controlled shock absorbers, speed-sensitive hydraulic power steering and M-performance stability, anti-lock braking and transmission programming. The M6 Gran Coupe will shoot from 0 to 60 mph in only 4.1 seconds and easily reach its electronically-limited top speed of 155 mph. It also boasts fuel efficiency with an average mileage of 28.5 miles per gallon. This feat of German automobile engineering is expected to make an auto show debut at either the 2013 Detroit NAIAS in January or the 2013 Geneva show in March.