BMW ActiveHybrid 5 Series Uses Next-Gen Hybrid System

In 2011, BMW will offer its third ActiveHybrid model when a 5 Series hybrid joins the ActiveHybrid X6 and ActiveHybrid 7 Series already in production. The BMW Concept 5 Series ActiveHybrid, based on the new 5 Series sedan, debuted at the 2010 Geneva Auto Show.

The new 5 Series hybrid uses the TwinPower Turbo inline six-cylinder engine that powers the 535i. The twin-scroll turbo produces 300 hp and is mated to an eight-speed automatic transmission. Specifically designed for this model, the compact hybrid system is located between the engine and transmission. An automatic clutch between the engine and motor allows disengagement so the Concept 5 Series ActiveHybrid can operate in an electric-only mode. This feature is not available in the ActiveHybrid 7, but is available in the ActiveHybrid X6, which uses a different two-mode active transmission.

The car’s low emission and performance capabilities are enhanced with a more powerful electric motor – 54 hp versus the 20 hp one in the 7 Series variant. A larger high voltage battery, probably a lithium-ion one like that used in the 7 Series hybrid, will be installed within a high-strength special case near the rear axle. This results in an optimum location for both safety and weight distribution.

The 5 Series hybrid has both Brake Energy Regeneration and Auto Start-Stop. According to BMW, the regenerative braking system is more efficient and thus generates greater electrical energy. All electrically powered equipment like the audio, climate control, and navigation systems are still fully available with the engine switched off. Auxiliary equipment is powered by the high-voltage battery including the climate control system, which can be activated remotely to heat or cool the interior. Even the engine can be started remotely.

BMW expects that this hybrid system will reduce both fuel consumption and emissions by more than 10 percent while retaining the BMW driving experience. Used together, the engine and motor provide even better performance than the already very capable non-hybrid 535i, especially at low speeds where electric motors provide immediate torque to bolster acceleration.

Finally, the Concept 5 Series ActiveHybrid’s energy management system fuses information from the engine, chassis sensors, and onboard driver assistance systems including on-board navigation. This information is used to optimize the interaction of the drivetrain components, not only for current driving conditions but also for upcoming driving ones. For example, if there is a downgrade ahead, the regenerative braking system would be ready to recover the maximum amount of energy to send back to the battery.