Currently reading: BMW reveals new Power eDrive plug-in hybrid system
Performance-oriented petrol-electric set-up develops over 670bhp and could be used in future Rolls-Royce models, including the firm's planned SUV

BMW has revealed an advanced new plug-in hybrid system, dubbed Power eDrive.

The new system forms part of an extended range of modular hybrid powertrains being developed in a performance-based EfficientDynamics engineering program at BMW’s research and development centre in Munich. 

It's envisaged for launch on various BMW Group production models in what BMW describes as “upmarket segments”. The unveiling brings closer to reality the prospect of a four-cylinder petrol and twin electric motor-powered model from Rolls-Royce. Such a model would be capable of impressive straight-line performance and increased range.

The new hybrid system aims to provide the sort of smooth yet urgent step-off performance qualities delivered by a contemporary battery-powered electric drive systems – like that offered in the Telsa Model S

An overall range of over 370 miles is quoted, with some 62 miles managed on electric power alone thanks to a range extender function.

Revealed in a 5-series GT-bodied prototype, the most powerful of BMW’s new modular hybrid powertrains uses its new 228bhp turbocharged 2.0-litre, four-cylinder petrol engine in combination with two electric motors. 

Those motors are a modified version of the i3's synchronous unit. A 201bhp motor is mounted up front in the space usually taken up by the torque converter in the car's eight-speed automatic transmission, while another, developing 268bhp, is mounted within the rear axle assembly.

In total, the system is claimed to produce over 670bhp, along with a torque loading beyond 750lb ft – figures that easily top the 453bhp and 530lb ft of the existing naturally aspirated 6.8-litre V12 used by the 11-year-old Rolls-Royce Phantom.

The principle behind BMW’s Power eDrive system is a maximisation of electric motor performance. “The electric motors provide approximately two-thirds of the combined output, with the combustion engine accounting for the remaining third,” said Franz Drescher-Kaden, BMW concept engineer for the new petrol-electric hybrid set-up.

Energy for the electric motors is provided by a 20kWh lithium ion battery mounted both longitudinally in the rear of the 5-series GT’s centre tunnel and horizontally underneath the rear seat in a space ahead of the rear axle. 

It can be charged both via plug-in means and on the run using the combustion engine in a steady state mode. The fuel tank has been reduced in size from a standard 70 litres to 30 litres.

As well as acting as a generator to produce electricity, the Power eDrive hybrid system’s petrol engine can also provide a performance boost with direct drive to the front wheels during kickdown, in which all three power sources are used for propulsion.

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Drive is nominally channelled to the rear wheels via the rear electric motor, whose reserves are sent through a multi-speed gearbox. 

The introduction of the front electric motor, which operates via the eight-speed automatic in which it is housed, provides all-electric four-wheel drive. This is further enhanced by the combustion engine, which also delivers its power to the front wheels.

BMW has not revealed a weight figure for its new hybrid system. However, it does concede that the addition of two electric motors, as well as the lithium ion battery pack and ancillary electronic management system, adds handsomely to the kerb weight. 

Despite this, BMW says the straight-line performance of its 5-series GT Power eDrive prototype exceeds that of the 444bhp twin-turbocharged 4.4-litre V8 550i GT, which tips the scales at 2070kg.

Power eDrive is being developed as developed as a scalable system with power outputs ranging from 250bhp to over 650bhp, according to BMW, which says the plug-in hybrid technology will be “a natural choice for use in upmarket vehicle segments”.

Among the new models thought to be in line to run the new petrol-electric system are future incarnations of the Rolls-Royce Ghost and Phantom as well as the firm's planned SUV – currently undergoing conceptual development.

BMW has also indicated Power eDrive could be offered alongside traditional petrol and diesel engine options in its upcoming X7 – a new range-topping SUV due for launch in 2017, as well as the next-generation 7-series, BMW X5 and BMW X6.  

Read Autocar's first drive in the new 3-series eDrive prototype

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JOHN T SHEA 28 November 2014

Motors too big for the battery?

"Despite this, BMW says the straight-line performance of its 5-series GT Power eDrive prototype exceeds that of the 444bhp twin-turbocharged 4.4-litre V8 550i GT, which tips the scales at 2070kg."

With 670 hp it certainly should, unless it weighs three tons!

And the commenters who think Tesla are going to beat the Germans in this decade remind me of those who thought Lexus would do the same in the last decade.

Pat75014 28 November 2014

Huge Progress but expected far too costy and heavy but we'll see

This is a Huge progress for BMW ! At last. I had lost faith to say the truth, planning to purchase a Tesla Model X as soon as in 2016.
Yet, it is not the desired / optimal Tesla like "all Electric Drive train" with dual Electric engines and an even smaller (non-tracting) BMW Range Extender ICE engine, and a larger battery pack, that could provide this type of capability at a much cheaper price, lower weight and w/ less complexity, PULLING the big central engine (Not pulled here, only downsized to 4xCyl), pulling the huge central gearbox (not pulled here), pulling the huge central transmission (reduced here but still there on the front, as this 4 Cyl ICE remains "tracting", still mechanically connected to the front weels). But its getting closer than ever to something I could purchase. Just that should end a lot more heavy and costy than needed, with potential greater maintenance costs due to the huge complexity of this drive train.
In any case this is by far superior to the ridiculous X5 eDrive concept presented at Paris motor Show last month, where I lost faith for BMW regarding EV & PHEV capabilities, and that I hope they will NEVER put in a production car, with its ridiculous 10KWH battery and 100HP single electric motor, copied from Porsche meaningless Panamera eHybrid non-sense, also pulling nothing, and at the end having the electric parts working as a sort of "Electric Turbo" mode, on top of 6 x Cyl ICE engine working de-facto all the time, as the all electric mode was just pityful.
On this Power eDrive I really love the 2 x Electric Motors both well > 200HP each, this is perfect BMW sizing for once ! But the battery remains too small with 20KWH. For me the minimum should be # 30KWH to allow one charge every 2 x days to perform my 65KM/day local commutes, so its 3000 x charge cycles can last longer. With 20KWH I'll need to charge every day so its 3K cycles will last # 10 Years, hence used resale value will remain bad. Still this is far better than 5-6Y with 10KWH non-sense of X5 eDrive. Then I hope that on the SUVs, where they may have more room and can allow more weight, they will keep a larger petrol trunk so for far away summer vacation trips with > 1K KM of high speed motorway per day, we don't need to stop at the pump too often, and get up-set by that.
Then we'll need to understand the details of everything and their Fast Chargers and Super Chargers compatibility... And the prices.
metanoid android 27 November 2014

This sounds promising

This 5GT mule is only an indication of what can be done with this emerging tech in a development of a current model.

BMW will be shedding considerable weight on their next generation platform (think it's called 3-5 up) starting with next years new G11 7 series. This platform will probably form the basis of the next Phantom. Using a combination of carbonfibre, aluminium and high strength steels, the weight of the new 7 is rumored to be less than a current 5 when powered conventionally.

I'm sure they must be trying to keep the weight of these new power e-drive models down to that of current conventionally powered models. The combination of hybrid tech with a lightweight platform will mean that BMW may well lead the way in this market.

As for engine choice, a four is acceptable for a 7 series these days (I even mused here at the possibility of using the i8 powertrain in a 7 a while back) but for a Rolls? I don't think so. More likely, they will use a V8 with a minimum of a 60 litre tank. It won't have the same packaging constraints as a 5 GT.

62 miles max electric only range is pretty decent though it might struggle to complete a lap of the Nurbergring if all that electric only performance is exploited!