The idea behind the new plug-in petrol-electric hybrid Power eDrive system is to provide a scaleable basis for BMW‘s future performance and upper luxury car needs.
The German car maker isn’t pretending the complex arrangement is going to replace the potent 552bhp twin-turbocharged 4.4-litre V8 direct injection petrol engine in the BMW M5 any time soon.
However, it does concede electrification is set to play an important role, both in achieving the sort of performance and range customers have come to expect from traditional combustion engines and at the same time fulfilling ever-stricter fuel consumption and emission regulations.
Right now, it says the Power eDrive system can be adapted to generate anything from 250bhp all the way up to 650bhp, as sampled here.
As an indication of where the efforts of BMW’s concept driveline engineers are focused with Power eDrive, the otherwise innocuous-looking 5-series GT xDrive in which the initial prototype system is installed is described to us as “the Tesla-killer”. We take a passenger seat and ready ourselves to ride shotgun around the German company’s vast Miramas test track in southern France.
From rest in the pit lane, the BMW test driver pushes the throttle against its backstop and we’re thrust onto the circuit with truly astonishing force. With the two electric motors channelling their reserves to all four wheels, acceleration is brutal.
The delivery of torque is instant, and it is sufficient to induce momentary wheelspin from all four wheels as we’re furiously propelled up the straight. The only sensation of noise comes from a distant high-pitched whine from the electric motors, the buffeting of wind around the exterior mirror housings and the roar of tyres across the Tarmac. That is until until the four-cylinder petrol engine fires to further boost the remarkable performance and also act as a generator to produce electricity, which is stored on board.
BMW won’t say exactly how much shove is on offer, suggesting only that it is “well into four figures” on the Newton metre (Nm) scale. As a point of reference, the recently unveiled performance variant of the Tesla Model S, the so-called 85kWh, possesses a mighty 931Nm – or some 687lb ft of torque. So the BMW prototype is not exactly lacking.
Make no mistake, this is a very heavy car. It carries three powerplants and a battery roughly twice the size of that found in more conventional plug-in petrol-electric hybrids. However, its ability to gather speed in a straight line is nothing short of sensational. Subjectively it feels every bit as quick (and then some) as the 3.2sec figure Tesla quotes as the 0-62mph time of the Model S 85kWh.
Before the weight becomes a factor, though, the BMW test driver steps off the throttle on the approach to the first corner and uses the brakes to recuperate electrical energy, allowing the big five-door liftback to roll past the apex before getting back on the power again for another viscous whip of acceleration along the next straight.
Once again, we’re left reeling from the sheer explosiveness of the available performance. That, and the already impressive cohesion evident in the complex driveline. Although it was hastily constructed, the driveline of the 5-series GT xDrive prototype gives the impression of being tremendously well engineered.
BMW won’t be drawn on specifics, but I suspect we haven’t seen the last of Power eDrive. What chances of the German car maker applying a modified version of its new plug-in petrol-electric system to the BMW i8 to create something really special – a centenary birthday gift to itself in 2016, perhaps?
from Autocar RSS Feed http://ift.tt/15H8jb7
via AGYA
