|BMW’s hybrid prototype in 2003 delivered strong low-end performance.|
BMW apparently is ready to show the supercapacitor-based gasoline hybrid it had discussed earlier in the year. (Earlier post.)
According to a report in Automotive News Europe, BMW will bring the hybrid concept car to the IAA show in Frankfurt in September. (IAA is going to prove to be the venue for a number of new “power” hybrid concepts, such as one expected from Porsche.)
BMW built a predecessor of this concept in 2003 when it integrated an electric motor between the engine and transmission to create a hybrid for acceleration assistance in a BMW X5 Experimental Vehicle.
The use of high-performance capacitors rather than batteries enables a more powerful, short discharge for the electric motor that can significantly add to the performance of an engine at low revs.
BMW found that the Experimental X5 “showed a standard of response never seen before” as well as an increase in torque to 1,000 Nm (737 lb-ft) at low speeds. The chart above plots the results. (Click to enlarge.)
The vehicle also reduced its fuel consumption by up to 15% in the usual test drive cycle.
As a result of those trials, BMW began exploring the creation of a compact “active transmission” integrating both the electric motor and the power electronics into the transmission—significantly reducing both the additional weight and the space required for the system. High-performance capacitors in the door-sills would provide the desired higher charge and discharge rates than a battery system.
That is likely what BMW will show in Frankfurt—built, perhaps, into an X3.