BMW has already announced two hybrid vehicles that will debut at the 2009 Frankfurt auto show, so the fact that its latest concept is also a hybrid shouldn't be terribly surprising. However, we didn't expect the Vision EfficientDynamics concept to be a turbo-diesel hybrid that uses a lithium-polymer battery pack and be capable of a 0-62 mph sprint in a mere 4.8 seconds. If the M division ever decided to build a hybrid the results couldn't be too different from what we see here.
The soul of the Vision EfficientDynamics concept is its 1.5-liter three-cylinder turbo-diesel engine and plug-in hybrid components. Using the diesel engine alone, the car has 163 hp and 214 lb-ft of torque thanks to technologies such as high-pressure direct injection and variable intake geometry. BMW managed to squeeze the little diesel engine ahead of the rear axle, but behind the rear seats for better handling characteristics and aerodynamic considerations. Power is sent from the engine to the rear axle through a six-speed dual-clutch automatic transmission, or "DCT" in BMW-speak. An electric motor is sandwiched between the engine and transmission and is capable of adding 51 hp and 214 lb-ft of torque to the total output. The electric motor can be used to power the vehicle without any help from the diesel engine when the battery has enough charge. Naturally the motor makes regenerative braking possible and feeds power back into the lithium-polymer battery pack during coasting and braking situations. Another electric motor can power the front axle and is rated at 80 hp and 162 lb-ft of torque for continuous operation. For 30 seconds, the output can be increased to 112 hp and 139 hp is available for a 10 second burst. A single-speed transmission sends this power to the front wheels and enables all-wheel drive.
BMW claims the Vision EfficientDynamics concept can run on power from the diesel engine alone, the electric motors alone, or with any combination of those sources. When maximum thrust is called for, like in passing situations, the combined output of the engine and two motors is 356 hp and 590 lb-ft of torque. Quite impressive when you remember this is only a three-cylinder engine displacing 1.5-liters. Perhaps the replacement for displacement is technology, electric motors and a 3076 pound curb weight.
Outside, the BMW Vision EfficientDynamics concept looks very futuristic and aerodynamic. Part of that look is related to the new layering technology that allows the exterior of the car to be nearly seamless and very lightweight. Flowing lines serve an aerodynamic purpose as well as looking cool -- the A-pillars send air around the cockpit past the rear spoiler to minimize turbulence and increase efficiency. The doors open up and forward and are made of three layers of materials. First is a layer of glass on the outside, then a structural layer to keep occupants safe in a crash, and finally an interior panel that serves as an armrest. LEDs are used for the headlights and taillights, which makes it possible for the taillights to be an integral part of the rear spoiler. The LEDs are always red in the rear, but glow yellow when the turn signal is activated.
Inside, there's an advanced heads-up display that shows information in three dimensions. This technology allows gauges to always be displayed in the background, even when important navigation instructions pop up and dominate the display. Of course the display could be configured to allow the navigation instructions to take a back seat to the gauges or other information to suite an individual driver's taste. Seating is a traditional 2+2 layout, and there's still enough room to bring two golf bags in the trunk area. If more room is needed, the rear seats can be folded down.
Surprisingly, the vast majority of the hardware on the Vision EfficientDynamics concept could be produced today. We've already got turbo-diesel engines, electric motors, and lithium-polymer battery packs being used in separate applications. Combining the three, along with all the lightweight materials, would likely be hugely expensive, but not impossible. Thankfully BMW has figured out a way to provide the fuel economy our politicians want and the performance enthusiast's desire in one package. Now we just need to wait and see if it will be built.