BMW will begin applying a new regenerative braking system technology to MINI hatch models to improve fuel efficiency and emissions. The MINI Cooper D—already the most fuel efficient of the line—will offer fuel consumption of 60 mpg US and CO2 emissions of 104 g/km.
BMW’s Brake Energy Regeneration uses a new lead-acid battery for energy storage. The braking technology reduces drag on the engine by only engaging when required to charge the battery, whereas a traditional alternator is always pulling power from the engine.
Additionally, the energy generated by the engine on over-run (under braking or descending a hill) was previously wasted. Now this lost energy is utilized to charge the battery.
