The close and direct link of concepts combining the new Sports Activity Coupé with innovative BMW ActiveHybrid technology ensures an authentic match of design and technology in every respect. The potential of BMW's ActiveHybrid system develops its optimum effect in the unique concept of the Sports Activity Coupé. This holistic, all-round approach sets the stage for an all-new driving experience.
The combination with innovative hybrid technology offers the most sporting and dynamic rendition of a BMW X Car. Design language typical of BMW takes up the superior driving dynamics of the Sports Activity Coupé and visualises this superiority through authentic design and a unique look. Indeed, the extravagant design of the body combines the sporting elegance of a BMW Coupé with the striking DNA of BMW X and provides a clear reference to the innovative drive concept.
The driving experience in BMW Concept X6 ActiveHybrid corresponds to the character of a typical BMW based on supreme dynamism and performance on the road. The car responds directly, spontaneously and with outstanding precision to the driver's commands, offering the driver perfect feedback at all times through touch effects and acoustic signals, like on a car with a conventional combustion engine.
BMW ActiveHybrid is a particular highlight of BMW EfficientDynamics, BMW's trendsetting development strategy for today's world. Introducing this technology, BMW is taking the next step in the ongoing reduction of fuel consumption and emissions. BMW ActiveHybrid is based on a modular concept following the strategy of "Best of Hybrid" to integrate the most appropriate, optimum components in each case in different concepts.
Interacting with the two-mode active transmission, the concept, through electrical support, offers two operating modes, one for setting off and driving at low speeds, one for higher speeds. This ensures optimum use of the torque generated as a function of driving conditions.
The innovative two-mode active transmission allows variable power transmission via the power split incorporating planetary gearsets. In addition, the active transmission incorporates an electric drive system and enables the vehicle to drive at fixed transmission ratios within one system. This combines the driving dynamics and efficiency of the combustion engine and the electric drive system in an innovative, intelligent manner.
The powerful presence of the car's body forms an ideal match with the flat, sleek flow of the greenhouse roofline. Indeed, this flowing roofline is a characteristic feature of the car's coupé silhouette, just like the short front overhang, the long wheelbase and the long rear overhang. In its design, BMW Concept X6 ActiveHybrid boasts all the DNA and genes so characteristic of the BMW X philosophy. The visual balance of the front and rear wheels to be admired clearly from the side, makes a clear reference to BMW xDrive, BMW's intelligent all-wheel-drive technology.
The second element dominating the design of the body is the clear orientation to the wheels, the muscular wheel arches and the large wheels clearly bearing testimony to the stable position and road-holding of the car. The dynamically rising contour line at the side and the growing distance between the shoulder and the sill-line as the vehicle moves back create a dynamic wedge shape.
The striking front view with a clear focus on the vehicle's width again provides the typical look of a BMW X car further emphasised by the extra-large BMW kidney grille also serving as the air intake with its robust slats. The engine compartment lid comes with clearly shaped contours sub-divided by sharp lines and tapering towards the BMW kidney grille, as well as a powerful curvature at the top with that striking BMW power-dome.
Through their unique shape and design, the D-pillars provide a clear expression of power and stability. The innovative design of the rear lights, in turn, emphasises the sheer width of the car, while horizontal lines highlight the wide track. The underfloor protection panels front and rear are made of brushed aluminium, the rear underfloor panel moving out when required and covering the tailpipes on BMW Concept X6 ActiveHybrid while driving on electric power only.
Door cutout trim with blue stripes and the name "BMW ActiveHybrid" clearly refer to the unique drive concept of this equally unique vehicle. The light colour of the body, in turn, forms a clear contrast to the dark window graphics, and the 21-inch wheels come in innovative, three-dimensional rim design.
The mild hybrid solution in the BMW Vision EfficientDynamics uses a compact generator that, for the first time, is flange mounted directly onto the gearbox. This motor produces up to 20hp of on-demand power. In addition, BMW’s now familiar Brake Energy Regeneration is used to efficiently capture energy that would previously have been lost when the engine is on overrun. Innovatively, the alternator is also integrated into the crankcase rather than conventionally driven from the front of the engine.
BMW’s concept uses highly efficient lithium-ion batteries in the boot area to store the power generated. These high-storage-capacity batteries enable optimum use of Brake Energy Regeneration. In addition, they create possibilities to power the air conditioning, electric coolant pump and the electric power steering system. For these functions, a 120 volt vehicle power system was designed and runs in parallel with the conventional 12 volt system.
The power harnessed by the batteries is also supplemented by roof mounted photovoltaic solar panels, measuring 1.0 metre square. The energy generated can either be used immediately or stored for later use. Importantly, the power created in this zero- CO2 way can be used to pre-heat the diesel fuel. The less efficient warm-up phase is thus shortened considerably.
What is Regenerative Braking?
When you hit the brakes, the car's kinetic energy is converted to heat through friction –throwing away the energy that was previously used to accelerate the car. In city driving, about 30 per cent of a typical car's engine output is lost to braking. This proportion drops to almost zero in highway driving, where braking is much less frequent.
In the case of a heavy truck, the heat that causes parts of its brake system to melt and create smoke comes from friction. Traditional brake systems grip metal disks or drums, using friction to slow or stop the rotating wheels of a vehicle. The friction of the brakes resists the forward momentum of the whole vehicle, and that friction creates heat.
In order for something to heat up it takes energy. The energy that heats up a truck's brake system comes from its momentum, speed, and mass. Where does a truck's momentum come from? It comes from fuel. Traditional brake systems, like those on large trucks, waste energy by converting forward momentum into heat.
One of the energy efficiency advantages of hybrid-electric technology over traditional is regenerative braking. A hybrid-electric vehicle uses an electric motor to create torque to drive its wheels. Interestingly, electric motors can be designed to be virtually identical to electric generators. This means an electric motor can either use electricity to create torque, or reverse the process to use torque to create electricity.
This "reversability" of electric motors is very different from the internal combustion motors in most cars. Can you imagine turning the wheels of a typical car backwards and having gasoline pour into the tank? Essentially this is what happens when you put your foot on the brake of a Toyota Prius or Honda Insight hybrid-electric vehicle.
When a hybrid-electric vehicle is approaching a stop light, it does not create friction and useless heat in order to slow down. Instead it reverses its electric motor turning it into an electric generator, creating electricity which is fed back into a battery and stored for when the light turns green. In fact any time a hybrid-electric vehicle slows down, lifting the accelerator or application of the "brake" causes the system to use the vehicle's momentum to generate electricity.
Hybrid-electric vehicles with regenerative braking can save a great deal of energy when compared to traditional cars, especially in "stop-and-go" driving situations.
[Source: Rocky Mountain Institute]
