When the first-generation BMW M5 arrived in the U.S. in 1987, it essentially created a new class of high-performance sedan. The super sports sedan concept continued to evolve reaching the point where the last-generation M5 came with a Formula 1-inspired V-10 engine, but its clunky single-clutch paddle-shift gearbox and weighty chassis disappointed.

Since then, others have upped their game and stolen the limelight. Not one to give up easily, BMW is set to unveil the M5 concept at the 2011 Shanghai  Auto Show. This car is poised to reign supreme once again in the world of blazingly quick 4-doors. A reign, might we add, that will allow for five full-sized adults to sit comfortably.

Proper credentials for any sports sedan always begin with the engine. And the new fifth-generation 2012 BMW M5 will come with a twin-turbocharged V-8, similar to the powerplants currently seeing duty in the X5 M and X6 M. No specific power output information was given by BMW at press time, but we’re pretty sure that the racy higher-revving 4.4-liter twin-turbo V-8 will crank out around 555 horsepower, a figure higher than the 507 bhp found in the previous naturally aspirated, V-10-powered M5.

And even with the extra output, the new engine will get better fuel economy than its predecessor, with emissions reduced by 25 percent – an improvement assisted by the Auto Start Stop function that temporarily shuts down the engine during idling. Release the brake and the V-8 engine comes back to life, immediately.

Putting the power down for the new M5 will be the 7-speed Double Clutch Transmission (DCT). To achieve sports car-like balance and handling, much of the suspension and active rear differential tuning, as expected, was done at the Nürburgring’s Nordschleife. With the Active M Differential varying torque to left or right wheels and weight-optimized brakes, expect performance numbers to exceed that of the older M5. Light-alloy double-spoke forged wheels are standard on the car, shod with 265/35ZR-20 tires all around. The gap between the wheels and flared wheel arches is narrowed over the regular 5 series, courtesy of the M-specific lowering.

The new M5 sports a muscular look thanks to its sculpted front end supported by larger, more aggressive air intakes to allow for the engine’s higher cooling needs. The subtle lip on the rear decklid, combined with the quad exhaust and rear diffuser, hint at the car’s prowess. Expect to see the new M5 on the road late this year or early 2012. Although it’s been labeled officially as a “concept” from BMW, the production version should see only minor variations. We can’t wait to sample it ourselves