BMW’s plug-in hybrid system for its regular models uses an electric motor integrated with the transmission. This motor is powerful enough to drive the car on its own but can also be used to aid an internal combustion engine during high loads. It’s powered by a lithium-ion battery stored in the trunk, which can be charged up at home or on the run using regenerative braking or energy from the engine.
The particular setup destined for the 3-Series plug-in hybrid is similar to the one in the X5 plug-in hybrid, as it relies on a turbocharged four-cylinder engine for its internal combustion component and an electric motor integrated with the vehicle’s eight-speed automatic transmission. But unlike the X5, here the drive goes to the rear wheels only.

2016 BMW 3-Series eDrive plug-in hybrid prototype
We’re likely to see the 3-Series plug-in hybrid, likely to be badged a 330e, debut in the second half of the year. Its arrival will coincide with that of the 3-Series’ mid-cycle update, set to be introduced for the 2016 model year. A debut of the complete range could take place at September’s 2015 Frankfurt Auto Show, with sales to commence shortly after.
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