BMW set a high bar for their Vision Concept: M3 performance and high MPG. The end results is a diesel hybrid with 356 horsepower. The technology underlying the Vision EfficientDynamics Concept offers a tantalizing view of what to expect in the future from BMW, and there’s a lot to be excited about.
As this is a hybrid and a sports car, we’ll start with the drivetrain. The Vision has a 1.5-liter three-cylinder turbocharged diesel engine which is, at its simplest, basically BMW’s 3.0-liter diesel V6 cut in half. Despite its size, this three-cylinder still puts out 163 horsepower and 214 lb-ft of torque. And, because of that small size, it can actually be mounted behind the rear passenger seat, making the vision a mid-engine mounted sedan. Just like in the BMW ActiveHybrid 7 that we looked at a few weeks ago, the internal combustion engine is mated to a small electric motor/generator that produces 33 horsepower and also acts as a drag brake on the engine to slow the car and produce electricity whenever you apply the brake pedal.
While that setup alone is impressive for the amount of power it can generate while buring little fuel, the Vision has another trick up its sleeve: an 80 horsepower electric motor that drives the front axle while the diesel and mated motor drive the rear. All told, the various parts of the drivetrain add up to a total power output of 356 horsepower and 590 lb-ft of torque which, according to a BMW press release, will accelerate the Vision from 0-to-60 mph in 4.8 seconds and manage an combined average fuel economy of 62.6 mpg.
Of course, with two electric motors onboard, you need plenty of juice. Some electricity will come from regenerative braking created by the electric motor/generator mated to the diesel engine, but most will be stored in the large battery pack that is built into the floor of the car and is charged by plugging the car into an electrical outlet. The system is similar to that used in the Chevrolet Volt, but it is more efficient. The amount of usuable energy stored in the BMW Vision is 8.6 kWh (kilowatt hours), which is about the same as the Volt. However, energy storage and battery capacity are two different things, determined by production architecture and materials. The Volt has a battery pack has a capacity of about 16 kWh while the BMW’s is 10.8 kWh. Without getting too in depth, the Vision and the Volt can hold about the same amount of electricity, but the Volt needs a much bigger battery to do it. As a results, the Vision’s battery weighs in at only 187 pounds and can be completely recharged from a European-standard 220-volt line in 2.5 hours.
The true genius of the Vision is in its integrated drive system. The car can run on the diesel engine, the smaller electric motor, the large electric motor, or any combination of the three. Pure electric range clocks in at 31 miles before the batteries go kaput, at which time the diesel engine kicks on. The 6.6-gallon fuel tank holds enough diesel to drive the Vision for 400 miles. For those counting at home, a gallon of diesel currently costs around $3, so that 400 mile range would cost $20.
The design, as you can see from the photos, is pretty advanced and Sci-Fi, but everything is there for a reason. In order maximize the fuel economy of the car, BMW had to make the most aerodynamic body possible. Even the A-pillar, the structural element between the windshield and door, is designed as a duct that will smoothly funnel air over the top of the car and down to the taillights, making it cut through the air more easily. BMW states that the drag coefficient (the amount of air resistance generated when an object moves through the atmosphere) is a paltry 0.22. For comparison, the slick new Nissan 370Z coupe has a coefficient of 0.30 and on the high end of the spectrum, a Hummer H2 clocks in at 0.57. This styling is probably too out-there to make it to the final production phase (should the Vision ever see production), but even modest changes to the design will still make this one of the slickest cars around.
As an item of engineering precision, the BWM Vision is nearly unparalleled. Combining the frugal, fuel-sipping mentality of a hybrid with the performance of the standard BMW lineup is no easy feat. The Vision, as a whole, will probably never see production, but bits and pieces of it are sure to show up in BMW models of the near future. As mentioned before, the new ActiveHybrid 7, which is set to hit dealerships next year, already incorporates similar technologies, put that’s the tip of the iceberg. By combining small, clean, diesel engines with electric motors, BMW can make production hybrids that can win drag races. And that’s no easy feat.