BMW is renowned for pushing back automotive boundaries and the new BMW X5 M and X6 M are two models that set a new benchmark. Never before has the marque offered such powerful and dynamically capable vehicles in a four-wheel drive package with a command driving position. As the first xDrive four-wheel drive cars, the BMW X5 M and the X6 M are a journey into new territory for BMW, while the twin-turbocharged 555hp V8 engine heralds the launch of the most powerful road-going M car the company has ever launched.

The new range flagships to the X5 and X6 portfolio are both powered by the same 4,395cc twin turbocharged V8 engine producing a maximum power output of 555hp at 6,000rpm. Such prodigious performance equates to a zero to 62mph time of 4.7 seconds – comparable to the critically acclaimed BMW M3. The X5 M and X6 M, courtesy of twin-scroll twin-turbo technology, are also capable of near diesel-powered engine flexibility with a peak torque of 680Nm from just 1,500rpm through to 5,650rpm.

Aiding the high performance characteristics of both vehicles is the unique configuration of the V8 engine. In a world first for an M badged vehicle, both the turbochargers and the catalytic converter are located within the vee of the powerplant. This arrangement results in an engine that breathes better and operates at a higher efficiency due to the shorter exit manifold. It also results in better packaging as the unit is more compact. The 4.4-litre engine features High Precision Direct Injection technology with piezo crystals for the optimum in fuel efficiency and combustion characteristics. As a result the powerplant for both cars meets the latest stringent EU5 emissions regulations.

Transmitting the power to the road in the X5 M and the X6 M is a drivetrain incorporating a new six-speed M Sport Automatic transmission, the class-leading xDrive four-wheel drive system and Dynamic Performance Control, all refined by M GmbH engineers to suit the new high performance vehicles.

The M Sport Automatic transmission features an electronic management system that has been fine tuned to cater for the sporting demands of the vehicles. With the capability to select a Drive mode, a Sports mode and a Manual mode the driver can choose his preferred programme depending on mood and prevailing road and traffic conditions.

Enhancing the package is the specification of Dynamic Performance Control on both vehicles. Dynamic Performance Control is a new style of differential, that first appeared on the BMW X6, which diverts power to the driven wheels rather than brakes the spinning wheel. Its working thresholds on the X5 M and X6 M have been tweaked to permit for greater cornering capability.

Like every new BMW currently on sale, the X5 M and the X6 M come with elements of BMW’s award-winning EfficientDynamics programme fitted as standard. Brake Energy Regeneration, on-demand delivery of the air-conditioning and the volume flow control of the hydraulic fluid in the steering all serve to improve fuel consumption and CO2 emission figures.

The X5 M and X6 M customer can fine tune the chassis of their new vehicle for greater enjoyment. The customer can configure the Electronic Damper Control, Head-Up Display, Dynamic Stability Control setting and the degree of assistance from the Servotronic steering system. Via the M Drive Manager, a menu system that lets the driver tailor the car’s characteristics and is activated with a button on the steering wheel, the desired response of all these settings can be engaged with a single press of a button. Thus, the driver can have an outright sport setting on standby while riding in a more comfortable mode day to day. As the X5 M and the X6 M are true M cars they both feature the renowned Launch Control function for optimum acceleration from standstill available for use via the M Drive Manager function. All of this electronic architecture is co-ordinated by the Integrated Chassis Management system, a highly advanced electronic brain.

The BMW X5 M and X6 M both feature a suspension set-up of a double wishbone front and a four control arm integral rear arm suspension. This arrangement allows for the best configuration for on-road performance for this style of vehicle. Compared to the BMW X5 and X6, the M versions have a 10mm lower ride height, feature stiffer springs for a sportier ride and come as standard with a revised version of Adaptive Drive. This last feature sees the Electronic Damper Control work with an active anti-roll bar to counteract the natural lean of a vehicle in a corner or road imperfections that would normally unsettle the ride for those inside.

As is befitting vehicles from a stable of performance engineers, the striking exterior design underscores the sporting potential of the car, while serving an aerodynamic function too. There are a number of key M design traits. The bespoke 20-inch light alloy wheels featuring differently sized tyres front to rear, M-badged side gills on the front wing, quad exhaust pipes and discreet badging are all M hallmarks. Compared to the front profile of the original X5 or X6, the bodywork has been reworked to enhance the aerodynamic efficiency needed to provide the extra downforce a 555hp vehicle requires. The rear also features a revised rear valance to ensure the exiting airflow leaves the vehicle with the minimum of fuss.

Inside, and the interior of both vehicles is as luxurious as you would expect. Leather upholstery is complemented by M Sport seats, M leather steering wheel, M footrest, M specific instrument cluster, full electric seat adjustment, front seat heating, two-zone air-conditioning and a Professional Multimedia Navigation system incorporating BMW’s ConnectedDrive. This offers all buyers the latest hard disk based infotainment network with facilities ranging from pure navigation needs through to the Emergency Assist functions and MP3 music storage. A top-of-the-range 12-speaker HiFi system with 230 watts amplifier and, on the X6 M, an automatic tailgate, are also standard.

Despite the sporting nature of the vehicles both still offer a high degree of practicality. The BMW X5 M has a possible luggage storage capability ranging from 620 to 1,750 litres while the X6 M manages 570 to 1,450 litres of boot space. Six airbags and impact activated head restraints are standard, with High Beam Assistant and Adaptive Headlights available as an option, on top of five star Euro NCAP ratings underscore the safety credentials for both vehicles.

The BMW X5 M and BMW X6 M go on sale 24 October, 2009. Prices will be announced at a later date.