Wednesday, July 29, 2009

The New BMW X6 on the Roads

Introduction











The BMW X6 is a mid-size luxury Sports Activity Coupé released for sale in the second quarter of 2008 by German automaker BMW. The X6 was marketed as a Sports Activity Coupé (SAC) by BMW. It combines the attributes of an SUV (high ground clearance, all wheel drive and all-weather ability, large wheels and tires) with the stance of a coupé (bold styling, dramatic sloping roof). It is also BMW's first SUV only equipped with an automatic transmission.


About the company
It is built in BMW's North American plant in Spartanburg, South Carolina alongside the BMW X5 whose platform it shares. It is dubbed a Sports Activity Coupé (SAC) by BMW, and while slightly longer and wider than the X5, it is significantly lower and seats only four people. The concept model debuted at the 2007 Frankfurt Auto Show. The production X6 officially debuted at the 2008 North American International Auto Show in Detroit and Montreal International Auto Show, respectively. A hybrid version, the BMW Concept X6 ActiveHybrid, which will be the first such vehicle from BMW, was also announced. Later, in April 2009, the sporty X6 M version was announced, with a 555 hp 4.4-liter turbocharged V8.


Petrol engines

Initially, the BMW X6 was available in North America (Now released in the UK) in two variants. Both use twin-turbocharged engines. The top-of-the-line model is the xDrive50i which uses an all-new 4.4-litre twin-turbocharged V8 engine. It produces 408 metric horsepower (300 kW) between 5,500 and 6,400 rpm, and 600 N•m (443 ft•lbf) of torque over a wide range of between 1,800 and 4,500 rpm. It is the first production turbocharged V8 engine in the world to feature its turbochargers between the V section in the middle of the two banks of cylinders.
The other model is the X6 xDrive35i powered by the N54 3.0-litre twin-turbocharged inline-six gasoline engine, producing 306 metric horsepower (225 kW) between 5,800 and 6,250 rpm, and a peak torque of 400 N•m (295 ft•lbf) between 1,400 and 5,000 rpm. This engine also sees duty in the 1, 3 and 5 Series BMW cars.


BMW X6 M (2010)

It includes a twin scroll twin turbo version of BMW N63 engine with Cylinder-bank Comprehensive Manifold (CCM). Engine is rated 555 PS(547hp/408kW)@6000rpm and 680 N•m (502 lb•ft)@1500-5650rpm.
Other features include 6-speed M Sports Automatic transmission with aluminum pull-style paddles on steering wheel, M Dynamic Mode feature, 10mm lower Adaptive Drive suspension, 4-piston fixed calipers with 15.6" rotor at front and 4-piston floating calipers with 15.2" rotor at rear, 20-in alloy wheels with 275/40R20 front and 315/35R20 run flat tires, special gills in the front fenders, 20-inch light-alloy wheels.
The 2010 BMW X6 M has MSRP of US$89,725.
The vehicle was unveiled in 2009 New York Auto Show.


Diesel engines
Two diesel variants have been announced, and are expected to constitute as much as 90% of sales volume in European markets. The models are called the xDrive30d and xDrive 35d, respectively. They are powered by BMW's 3.0-litre turbodiesel engine (in its sequential twin-turbocharged variant for the xDrive35d), and produce 235 PS (173 kW) in the xDrive30d and 286 PS (210 kW) in the xDrive 35d version. The second of these power units will form the basis of BMW's Diesel launch in all 50 states in late-2008.



Dynamic Performance Control
The X6 marks BMW's first use of its new Dynamic Performance Control system, which works in unison with xDrive all-wheel drive (both are standard on the X6). DPC is a drive-train and chassis control system that works to regulate traction and especially correct over- and under-steer by actively spreading out drive forces across the rear axle. Torque is split not only between the front and rear wheels (xDrive) but also from side to side at the rear for improved agility and added stability (through the DPC rear axle).
The DPC differential features clutch packs on both output sides that are actuated by an electric motor. The clutch pack activates a planetary gear-set which causes one wheel to be overdriven. A conventional control system will use the brakes to reduce the speed of the faster moving wheel (which is the one with less traction) and reduce engine power. This leads to increased brake wear and slower than optimal progress. The DPC system speeds up the slower moving wheel (the one with the most traction) in order to maintain stability when needed. For example; while turning, the outer wheel is overdriven to provide greater acceleration using the traction advantage through the dynamic loading of the outboard wheel in cornering. In an over-steer situation, the inner wheel is overdriven to regain traction balance.
Dynamic Performance Control is currently unique in that it is effective when the X6 is both accelerating and decelerating, so at any speed and under any road condition.