After several months of speculation and official teases, we now finally have all the details on the Vision EfficientDynamics Concept that BMW showed in Frankfurt a couple of weeks ago. The speculation about the concept’s powertrain has gone in several directions, almost all of which were correct. The new concept is a plug-in hybrid with a three cylinder turbo-diesel engine. Conceived with the idea of melding the performance of an M3 with exceptionally low fuel consumption, BMW claims a 0-62 mph time of 4.8 seconds while scoring 62.6 mpg (U.S.) on the EU combined test cycle.
There has been considerable speculation that future BMWs would go to smaller engines including a three cylinder. The concept uses a 1.5-liter turbodiesel that is essentially half of the fabulous 3.0-liter found in the 335d. The triple is rated at a hefty 163 hp with peak torque of 214 lb-ft. The engine is paired with a 6-speed DCT derived from the unit used in the M3 and Z4.
Making use of electric motors requires some electrical energy system. Here BMW’s new concept has an arrangement similar to the Chevy Volt using a lithium polymer battery pack running down the center tunnel of the car. Also similar to the Volt, the pack has a usable capacity of 8.6 kWh. However, the total capacity is just 10.8 kWh. BMW claims the pack used in the concept can use 80 percent of its capacity, considerably more than the 50 percent that the Volt uses. The upside is that the pack weighs just 187 pounds. When plugged into a standard European 220 V / 16 A outlet, the battery can be charged in just 2.5 hours.
Unlike the Volt, which is designed to give its full performance from the electric drive system, the BMW concept gets it’s full capability from the blended power delivery. The concept is able to run about 31 miles on electricity alone and complete the NEDC test procedure on electricity. The efficiency of the diesel engine means that the 6.6 gallon tank can propel the car another 400 miles. The electrical energy consumption of the concept is 28.16 kWh/100 miles which compares to the claimed 25 kWh/100 miles for the Volt.
Another area where the BMW differs particularly from the original Volt concept is aerodynamics. The Volt is well-known for having had terrible drag properties. The BMW is claimed to have a drag coefficient of 0.22, part of which was attained by moving the diesel engine to the back of the car. The mid-mounted engine sits just ahead of the rear axle which combines with the small front electric motor for a very low front end. Similar to the Cadillac Provoq concept which eventually became the SRX, front air resistance is reduced by using thermostatically controlled slats ahead of the radiator inlets to redirect air when it isn’t needed for cooling. Overall, BMW has made use of knowledge gained from motorsports in optimizing the aerodynamics of the Vision EfficientDynamics concept.
Filed Under: Cars & Transport