We knew the BMW i8 plug-in hybrid (PIH) sports car was the tip of the BMW gasoline-electric hybrid iceberg. Beyond the i8, BMW has been teasing us with the X5 eDrive Concept and testing PIH prototypes where they knew spy shots would be taken and immediately transmitted worldwide over the Internet. The only real questions were when and which models?
At the BMW Group Innovation Days 2014, BMW announced the 3 Series plug-in hybrid prototype. It makes sense that BMW’s best-selling premium sedan has a big enough base that the number of potential PIH buyers would be large enough to make it worth BMW’s while to build one.
The 3 Series plug-in hybrid prototype combines a four-cylinder TwinPower Turbo gasoline engine from BMW’s new Efficient Dynamics engine family with an electric motor. This engine combination will provide the 3 Series PIH with power similar to that of BMW’s old, normally aspirated six-cylinder engine, but with much better fuel economy. The PIH gas/electric hybrid drive system would crank out 245 horsepower and 295 pound-feet of torque, while consuming about 117 miles per gallon. That’s right. One-hundred and seventeen empeegee.
If the trip is under 22 miles, the 3 Series PIH might get away with using no gasoline at all, as the car can cruise up to 22 miles at speeds up to 75 miles per hour, using only the electric motor.
The gasoline engine that partially powers the 3 Series PIH is based on the four-cylinder TwinPower Turbo engine that has already been named “International Engine of the Year”—twice. The electric motor is based on the BMW eDrive technology used in the BMW i3 and BMW i8 and powered by lithium-ion batteries that can be recharged at any household power socket—although we suspect a dedicated wall-charger would do it faster.
The internal-combustion and electric motors drive the rear wheels of the 3 Series PIH prototype through an eight-speed Steptronic transmission.
As a design exercise the 3 Series PIH prototype demonstrates that future BMW plug-in hybrids can offer the same practicality as conventionally powered versions of the same model. In the case of the 3 Series, the model is designed so that the added electric motor and battery result only in a minimum reduction of trunk space, and the interior configuration possibilities—such as fold-down rear seat backs—are the same.
Like the current 3 Series, the BMW 3 Series plug-in hybrid prototype gives the driver the ability to select different driving settings; specifically, Comfort, Sport, and Eco Pro.
In Comfort mode, the electric motor is computer controlled to support relaxed, fuel-efficient motoring. Sport mode gives the driver full availability of power from the gasoline and electric motors together. Eco Pro mode lets the car take full advantage of the electric motor to maximize range, while carefully managing high-draw electrical systems such as seat heating and air conditioning to operate at the most efficient power levels.
Drivers may also select between different plug-in hybrid modes. Max eDrive engages only the electric motor. Save Battery mode keeps the lithium-ion battery at a constant charge level to allow the driver enough battery power to switch to Max eDrive when it is most advantageous—in the city, for example.
BMW is big on driver assistance systems and the 3 Series plug-in hybrid prototype is no exception. The Proactive Driving Assistant is integrated with the navigation system and helps manage the powertrain’s electrical use and battery charging while taking into consideration the upcoming route profile, speed limits, and traffic conditions.
In terms of the seemingly glacial pace with which BMW brings to market cars that we really want to see, the 3 Series plug-in hybrid version may be just around the corner; perhaps as soon as next year as a 2016 model in conjunction with the expected 3 Series facelift. An X5 PIH can’t be too far off and BMW has also been testing a 7 Series PIH for many months.
BMW says its plug-in hybrid technology is so flexible that it can be rapidly integrated across the BMW model range. Efficient intgernal-combustion engines are getting more efficient. The i3 has proven the deasability of all-electric vehicles for urban mobility. Over the long term, BMW sees the possibilities of electric mobility in conjunction with hydrogen fuel cells.
The first BMW plug-in hybrid to follow the BMW i8 into actual production, however, will arrive much sooner—just not here. A 5 Series plug-in hybrid will be offered only in China. Badged as a 530Le, it is a long-wheelbase sedan that BMW is building jointly with Brilliance, its Chinese partner. The word is that the roomier back seat version is necessary in China to accommodate those owners who are chauffeured or haven’t learned how to drive. The 530Le drivetrain layout will be similar to the 3 Series plug-in hybrid prototype, but with a slightly more powerful powertrain at 272 horsepower.
The 3 Series seems like a good place to start the electrification options. Sporty yet comfortable and for many, a good compromise between the all-electric i3 and the conventional Bimmers. The question is, will it still be able to peg our fun meters like the 3s that preceded it. Are we ready for a run group at a chapter driving school in the not-too-distant future that’s completely silent except for the tire noise?—Scott Blazey
[Photos courtesy of BMW AG.]
