Described as combining the performance of an M3 with the economy of its European 116d model by a BMW insider, this latest concept car will be officially unveiled at the Frankfurt Auto Show in September. It represents BMW’s most radical step in its EfficientDynamics philoshphy, putting the fun into frugal.
The headline number include 356hp, 590 lb-ft, 155mph top speed, 0-62mph in 4.8 and fuel consumption of just 62.6mpg For decades, BMW has made the reduction of emissions and fuel consumption a key part of its product development strategy. Its EfficientDynamics program has pursued an enhanced driving experience while simultaneously lowering the consumption and emissions of each vehicle - resulted in the most dramatic drop in fleet consumption of any automaker from 1990-05, according to an Environmental Defense study.
Now, the BMW Vision concept demonstrates that EfficientDynamics can be applied to a sports car. Conceived as a 2+2 with plug-in full-hybrid diesel technology, the Vision combines the performance of a BMW M3 with fuel efficiency and emission that exceeds even the current levels achieved by the latest small cars. This was made possible by the combination of BMW ActiveHybrid components with an extremely economical combustion engine, and outstanding aerodynamics.
The Vision is the result of a "clean-sheet" development to ensure its efficiency, driving pleasure, technology, and emotional design. The powertrain provides a top speed limited to 155mph, with 0-62mph acceleration in 4.8 seconds. Average fuel consumption in the EU test cycle equates to 62.6mpg, and the CO2 emission rating is 99g/km. CO2 emission is outstanding when driving in the all-electric mode after charging the battery from a plug-in source: Taking all emissions in the generation of electricity into account, as prescribed by the EU formula, the emission rating is just 50g/km.
The power and performance are made possible by combining a fuel-efficient 3-cylinder, 1.5 liter turbo-diesel with one electric motor on each axle. The combination of these units means overall system output is 356hp, and peak torque is 590 lb-ft. The special arrangement of the two motors and diesel engine allows all-wheel drive in all-electric mode.
This is the first time a turbo-diesel has been used in an EfficientDynamics concept. Displacing 1.5 liters, the engine follows the downsizing principle of using a small turbo engine to reduce consumption. It’s mid-mounted in front of the rear axle, and yet there are two seats at the rear. Fuel is added by the latest High Precision Direct Injection, and the turbo has variable intake geometry for maximum efficiency. Engine output is alone is 163hp with peak torque of 214 lb-ft.
The specific output of 109hp per liter sets a new benchmark in diesel technology. Power is moved to the rear axle by means of a double-clutch six speed transmission (DCT).
The diesel is supplemented by two electric motors. In this concept, the driver benefits from the efficiency of the electric motors over a wider speed range than a conventional hybrid.
The rear axle has with a second-gen full-hybrid system corresponding to the technology in the BMW ActiveHybrid 7 model. The compact electric motor positioned between the diesel engine and the DCT outputs a consistent 33hp and is able to reach a peak of up to 51hp. Maximum torque for the rear electric motor is 214 lb-ft. It can either support the diesel engine or operate in all-electric mode.
When coasting or applying the brakes, the electric motor acts as a generator and feeds electric power to the lithium-polymer battery in the car. The electric energy developed in this way is captured without any additional fuel consumption through the principle of Brake Energy Regeneration.
A second electric motor acts on the front axle. This hybrid synchronous motor offers continuous output of 80hp and peak torque of 162 lb-ft. Extra power of 112hp is available for a period of up to 30 seconds. And it can develop 139hp for a 10-second "burst". The power is transmitted through a 2-stage, single-speed reduction gearbox.
BMW Vision is able to run under electric power, turbo-diesel power or an infinite combination of the three power sources. Depending on driving conditions, the two electric motors may be used both for accelerating and for regenerative energy when applying the brakes or coasting. When accelerating, the electric motors help to boost the performance, ensuring immediate response and a significant reduction in fuel consumption. For a short time, such as passing maneuvers, the cumulative maximum output of all three engines increases to 356hp, with maximum torque reaching 590 lb-ft.
The energy cells in BMW Vision are housed in the chassis running through the middle of the car. The front unit is the lithium-polymer complex, an ongoing development of the lithium-ion battery. It comes with a total of 98 lithium-polymer cells, each offering a capacity of 30 amp/hours and developing continuous output of 600 amps at 3.7 volts. For a period of 30 seconds, each cell is even able to develop maximum output of 1200 amps.
Serial arrangement of the lithium-polymer cells serves to generate nominal voltage of 364 volts, the gross storage capacity of the battery is 10.8 kW/h. With an unusually high discharge capacity of 80%, the battery delivers 8.6 kW/h for driving the car. This superior performance comes on overall weight of the entire energy storage system of just 187 lb.
A further advantage is that through their placement and energy management, the thermal load on the battery is reduced to such an extent there is no need for active cooling.
While Brake Energy Regeneration captures electric power, a further option is to charge the cells through a conventional power socket using a plug-in connector in the front-right of the car. Connected to a standard EU power outlet (220V, 16 amps), the system requires a maximum of 2.5 hours to fully charge the lithium-polymer cells. And wherever a power source with higher voltage and amperage is available, the charge time is even shorter.
In addition to electrical energy storage, BMW Vision EfficientDynamics comes with a conventional fuel tank at the rear of the central chassis tunnel, offering a capacity of 6.6 gallons. Running on diesel alone, the Vision concept is able to cover a distance of approximately 400 miles. Benefitting from an extra range of up to 31 miles in the all-electric mode, the car offers an overall range of approximately 431 miles.
In its exterior design, the concept differs from the usual low-emission car concepts. Measuring 48.8" high and boasting a sweeping roofline, the designers have succeeded in giving the car a very low front end, with the flow of air being smoothened by active louvers in front of the radiator, which close completely when not needed.
Numerous details in the design of the body are based BMW’s motorsport experience, such as air deflectors and guide vanes. Designed as ducts, for example, the A-pillars serve to channel the air flow in the same way as the rear lights with their wing profile. The floor of the car is covered from front to rear, thus maintaining a smooth surface to avoid turbulence. Slender openings around the front air dam guide the air specifically into two ducts leading into the wheel arches, where the air exits through a slim aperture at high speed, flowing next to the wheels. This air jet rests on the front wheels like a curtain and is referred to as the "air curtain", providing a stabilizing effect.
To further optimize the aerodynamics, the tires measure 195/55 on large 21" wheels. In combination with the sophisticated axle geometry, this ensures agile driving behavior.
The extra-large wheel covers extend over the tires to create another unique look for the BMW Vision EfficientDynamics. The blade profile integrated into the wheels further serves to reduce the negative effect of the turning wheels on the aerodynamics. In all, these features give the concept car a very low drag factor (CX) of just 0.22.
This continued lightweight construction can be seen in the design of the controls and switches, with a leather band, for example, running round the aluminum gear lever on the center console. The body-contoured seats have a kevlar shell, while the rear seats appear to be hovering in space. Natural materials and light colors on the seat upholstery and all interior linings underline the light and sustainable atmosphere within the passenger compartment.
LED lights at the front and rear of the Vision concept provide the distinctive look of dual round headlights. The rear lights are integrated into the entire rear section, forming part of the rear air deflector and merging into the entire contour.
Extremely flat and compact, the rear lights are LED units that form a smooth and consistent red surface when not in use. Only when used do the respective light chambers take on the appropriate color, such as yellow on the direction indicators.
The light source within the passenger compartment is fed from the lights at the side, rear and the brake lights, thus changing the atmosphere within the car as a function of driving. As a result, the conventional barriers between the exterior and interior are blurred. The lines within the interior, for example, continue into the engine compartment lid, while the third brake light follows the structure of the glass roof and tapers to the outside.
The doors pivots in the front roof column. Since the car has no B-pillars, the large door cutouts ensure convenient entry to the rear seats as well. The pivots on the doors also provide the base for the exterior mirrors.
The concept includes a 3D Head-Up Display providing the option to present various signals more in the front or more in the background, depending on their relevance and current driving conditions.
With the individual system components on board being networked with one another, it allows energy management using information gathered by the driver assistance sensors. Data provided, for example, by the rain sensor or Active Cruise Control with its Stop & Go function as well as by the navigation system, can be evaluated by the central control unit, offering an overview of current and upcoming driving conditions. Should the central computer detect, for example, that the driver is about to take the freeway, the power used to run the cooling system is reduced in advance, on the assumption that the short increase in coolant temperature will be offset by the higher speed of the car. Another example is the regeneration of energy from the air conditioning, from Electronic Power Steering and the Brake Assistant.
The technology in this Vision concept is a glimpse of the future and one we expect to see implemented by BMW in various forms over the next few years. Indeed, much of what we see here is a development of its existing technology. But certainly BMW is keen to package its green approach to motoring in an exciting vehicle that promises an entertaining future for car enthusiasts.