Purists can completely disable the M xDrive and DSC systems to drive in proper rear-wheel-drive mode.

BMW officially unveiled the sixth-generation M5--the first M sedan to be equipped with all-wheel drive--back in August, but we're getting our first up-close look at it in Frankfurt this week.

The M-specific xDrive system was designed to maximize driving dynamics, only engaging the front wheels when the rear wheels are unable to put all commanded torque to the road. An Active M Differential also helps avoid the need for engaging the front wheels or activating the DSC system, locking the rear differential in some scenarios to help maximize power delivery across the rear wheels.

The M xDrive system is said to enable a certain amount of wheel slip when accelerating out of corners. Purists can also completely disable the AWD and DSC systems to drive in proper rear-wheel-drive mode.

The latest generation TwinPower Turbo 4.4-liter V8 engine develops 600 horsepower above 5,700 rpm and 553 pound-feet of torque from 1,800 rpm through 5,700 rpm, delivered via a revised eight-speed M Steptronic transmission.

With a bit of help from the front wheels, the new M5 can launch to 60 mph in 3.2 seconds. It can reach 124 mph in just 11.1 seconds, eventually hitting 189 mph with the optional M Driver's Package.

"Thanks to M xDrive, the all-new BMW M5 can be piloted with the familiar blend of sportiness and unerring accuracy both on the racetrack and out on the open road, while also delighting drivers with its significantly enhanced directional stability and controllability right up to the limits of performance when driving in adverse conditions such as on wet roads or snow," says BMW M head Frank van Meel.

Despite the additional gear required for the xDrive system, BMW claims to have reduced heft by employing a carbon fiber roof and lightweight exhaust system, among other optimizations.

The M5 First Edition will lead the pack with a limited run of just 50 units in the US market. The first units are expected to arrive in showrooms by spring 2018, with pricing to be announced closer to market launch.