Like many automakers today, BMW->ke178 is also elbows deep into developing highly efficient vehicles with low or zero carbon-dioxide emissions. The Germans already have the i3->ke4694 electric car->ke1030 and the i8->ke4622 hybrid,->ke147 as well as a series of mind Activehybrid models, but Munich has expressed its intentions to launch more efficient vehicles with a range of newly-developed technologies. There have been rumors about BMW signing a partnership for batteries and parts with Tesla->ke1842 Motors and even the possibility of a hydrogen-fueled i5, but what we do know for a fact is that the Germans are working on a very efficient hybrid drivetrain that goes by the name Power eDrive.

Following the success of the i3 and the i8, BMW has developed a brand-new drivetrain that combines its proven turbo-four gasoline engine with a couple of powerful electric motors. BMW isn't gunning for efficiency alone, but it also wants to enable its future hybrid to deliver the performance customers are familiar with and more. Still in its prototype phase, the Power eDrive could be the most powerful BMW production powertrain ever at 680 horsepower and 750 pound-feet of torque. The combo is currently being showcased in the 5 Series Gran Turismo, but it could find its way into several BMW models, ranging from sedan to SUVs.->ke145 The Germans might even be planning a supercar->ke177 with this drivetrain, although the two electric motors and the battery packs are still far from being light enough for a vehicle above the i8.

It could take a few years to find out the company's specific plans for the Power eDrive, but in the meantime let's have a look at this brand-new drivetrain as showcased in the 5 Series GT prototype below.

Click past the jump to read more about the BMW 5 Series GT Power eDrive.

Exterior

The appearance of the 5 Series GT Power eDrive is that of a stock version with the M Sport package. Specifically, the hybrid is equipped with a sportier front bumper that includes larger air inlets, sharper side skirts and a modified rear apron. Larger 19-inch wheels are also present, but the design is different from the usual V-spoke or double-spoke layout that comes with the M Sport package.

Other than that and the "Power eDrive" decals on the doors, this hybrid prototype is identical to a conventional 5 Series GT. Exterior changes might occur when the vehicle goes into production -- starting with a few badges -- but BMW has yet to mention anything about its final design.

Interior

There are no photos of the interior as of December 2014, but we expect the cabin to remain unchanged as far as amenities go. Given the M Sport bits seen on the outside, I expect this hybrid to feature a sportier interior with bolstered seats wrapped in Dakota and Nappa leather, a multifunction steering wheel, and aluminum trim.

With 680 horsepower at its disposal, this Bimmer's interior would be quite inappropriate without the sporty features of the M Sport package. Heck, it's quicker than a full-fledged M version and some customers will put it through its paces on a race track at some point. To do that, they need proper seats, sports pedals, and everything that comes with a high-performance vehicles, hybrid or not.

Naturally, the Power eDrive features an updated infotainment system with display menus and setting typical to a hybrid car. Though BMW hasn't released any details, drivers should be able to monitor vital info such as battery usage, range, EV mode data and so on.

Drivetrain

This is where the 5 Series GT stands out when compared to its conventional siblings. Motivating the sedan is the company's familiar twin-turbo, 2.0-liter, four-cylinder engine -- not available on the U.S.-spec 5 Series GT-- and a pair of electric motors. While the gasoline unit pumps only 228 ponies, the electric motors crank out 201 and 268 ponies, respectively, taking the total output to a whopping 680 horses. The torque figure is equally impressive, with at least 750 pound-feet of twist spinning the wheels.

The combo enables the sedan to act like an all-wheel-drive vehicle. One 201-pony unit is mounted up front in the space usually occupied by the torque converter in the eight-speed automatic transmission, while the more powerful motor lies within the rear axle assembly. Both are powered by 20-kWh lithium-ion batteries installed longitudinally in the rear of the car's center tunnel and horizontally underneath the rear seats. The battery can be charged via the sedan's plug-in socket or on the run using the gasoline four-banger, which is now fueled by an eight-gallon tank instead of the standard 18-gallon.

When used in all-electric mode, the 5 Series GT Power eDrive is good for 62 miles. When this setting is activated, the 2.0-liter engine acts as a generator, but it can also boost performance by sending power to the front axle. When used as a classic hybrid, the sedan returns a range of more than 370 miles with a fully charged battery and a full gasoline tank.

As far as performance goes, BMW has yet to release any specs. However, the Germans did say the Power eDrive prototype is quicker than the 4.4-liter V-8-powered 550i GT, which needs 4.5 seconds to reach 60 mph from a standing start. That's quite impressive for vehicle that weighs significantly more than the regular 5 Series GT, mostly due to the added electric motors, battery and electronic management systems.

Drivetrain Specifications

Prices

With no actual launch date given, it's way too early to talk about prices. However, I do expect the Power eDrive to become the most expensive 5 Series GT once it arrives in showrooms. The title is currently being held by the 550i xDrive, which retails from $71,400. The base, U.S.-spec 535i model starts from $60,700.

Competition

Tesla Model S P85D

I know the Tesla Model S has no gasoline engine, but the 5 Series GT Power eDrive is powerful enough to compete against America's already iconic all-electric sedan, although the Bimmer is smaller than a regular full-size. The P85D is brand-new in the Tesla lineup and it's the quickest and most powerful Model S ever created. Unlike the regular sedan, which comes in a rear-wheel-drive configuration, the P85D is motivated by two electric motors, which means power reaches all four corners.

The unit spinning the rear wheels generates 470 horsepower and 443 pound-feet of torque, while the power unit mated to the front wheels sends 221 ponies and 244 pound-feet of torque to the pavement. This means the P85D has no less than 691 horses and 687 pound-feet of twist at its disposal, figures that return astounding performance. Specifically, the sedan can now sprint from 0 to 60 mph in only 3.2 seconds, making it quicker than the BMW above and faster than any other production sedan and a host of sports cars. Top speed sits at 115 mph. The AWD system also adds an extra ten miles to the range, taking the total up to 275 miles on a single charge.

That's nearly 100 miles less than what the 5 Series GT can return, but the Model S will run for 275 miles without a drop of gasoline, something the German sedan can't do. Pricing for the Model S P85D starts from $120,170 before incentives. Definitely not cheap, but the Tesla delivers performance and mileage other electric or hybrid vehicles cannot.

Conclusion

I've never been a fan of the 5 Series Gran Turismo -- a bloated 5 Series with a tailgate -- and I've yet to understand its actual purpose in the segment expect for the fact that it offers a lot of extra legroom in the rear. However, the addition of a hybrid drivetrain changes things dramatically, especially with 680 horsepower and 750 pound-feet of torque on tap.

Sure, that doesn't make it prettier on the outside, but we're now looking at a roomy, five-door GT that sips a lot less fuel and offers an outstanding range. Of course, it's still a prototype and it would be awfully expensive as a production car, but the 5 Series GT Power eDrive would give the Tesla Model S a run for its money. Not to mention that the Power eDrive technology will be offered in other BMW vehicles as well.