| GREEN POWER: BMW says the X6 ActiveHybrid is the world's most powerful hybrid car. |
By kazuyagaro
The hydrogen revolution so strongly promoted as recently as a year ago seems to be on hold as one of its greatest champions, BMW, joins the petrol-electric hybrid brigade.
This follows the launch of Toyota's third-generation Prius hybrid and suggestions that a host of other manufacturers will show their latest anti-greenhouse weaponry at the Frankfurt auto show in September.
Mazda seems to be the odd one out - it will launch a rotary hydrogen engine - but each is no doubt fearful of the consequences of global warming and the role they might be playing in it.
BMW has announced two luxury hybrids - an ActiveHybrid 7 and the BMW X6 ActiveHybrid whichm the automaker says, is the world's most powerful hybrid car
The BMW ActiveHybrid 7 combines a twin-turbo V8 petrol engine with a three-phase synchronous electric motor for a potential of overall system output of 342kW and 700Nm.
The company says this "intelligent" combination in a mild hybrid concept will promote the efficiency, dynamic performance and driving comfort of this luxury sedan with the hybrid 7 accelerating to 100km/h in 4.9sec and reaching a top speed - electronically limited - of 250km/h.
At the same time average fuel consumption will be a claimed 9.4 litres/100km but CO2 emissions of 219g/km.
BMW's hybrid technology featured in the 7 Series includes a three-phase synchronous electric motor, a lithium-ion battery and the power electronics required for the high-voltage network - state-of-the-art kit in hybrid technology
The electric motor - built into the automatic transmission - develops 15kW and 210 Nm and acts as a generator when the driver applies the brakes, delivering electric power to the battery in the boot.
The battery provides power to the electric motor when accelerating and ensures consistent of power to the air-conditioning compressor whether driving or standing still.
And, of course, it also provides the power required for the conventional 12V network.
BMW's engineers say the electrical power is generated in a "neutral" process without consuming any extra energy.
REDUCING CONSUMPTION, EMISSIONS AND NOISE
When accelerating, the electric motor boosts the V8 engine by providing extra power but it reduces the level of petrol power required when driving at a steady speed, cutting fuel consumption, emissions and engine noise.
Using it as a starter ensures that the petrol engine will start immediately without the slightest vibration - ideal for the auto stop-start function - and the aircon will run on the battery with the petrol engine switched off, to set the interior temperature to the desired level before setting off.
Energy flow and efficiency displays in the cockpit inform the driver of the operating status and function of the hybrid drive system.
BMW has also introduced off its first full-hybrid SUV, the S6 ActiveHybrid, which it says uses 20 percent less fuel than a comparable vehicle powered by a combustion engine alone.
BMW recently called CarAdvice to see if we were interested in participating in a car challenge of a different variety.
Instead of seeing who was quickest around a track or who could post the fastest speed, BMW enlisted their latest Efficient Dynamics vehicle – the 120d – and sent 16 motoring journalists, in four separate groups, through a set of challenges that would test the vehicle’s efficiency, along with its sporting edge.
The four stage challenge began with a ‘dynamic drive’ that had the contingent of journalists drive from BMW’s Melbourne headquarters to Phillip Island, with a detour through Poowong and the mountainous greenery that followed.
The first stage was to show drivers that the 120d, although currently BMW’s most efficient vehicle, is still a driver’s car at heart. Corners were eaten up and spat out with very little effort – even with the torrential Melbourne downpour that followed us for most of the day.
Most drivers averaged between 4.0-litres per 100km and 5.0L/100km, varying according to their average speed.
The dynamic drive portion of the day gave me a chance to get in tune with the 120d and see what it was all about. Priced from $46,790, the 120d Sport Hatch packs 130kW from its 2.0-litre turbocharged diesel engine. While the power is impressive, the equally impressive 350Nm of torque means the 120d dashes from 0-100km/h in just 7.6-seconds.
The vehicle feels in tune with the road and the driver at all times. Its penchant for frugal motoring doesn’t overcome the car’s ability to motor along with grace and pride – like all other offerings from BMW.
The steering is precise and while slightly heavy provides fantastic feel with the road. The test vehicle that I called home for the day was fitted with leather upholstery (beige, or lemon in colour as BMW like to call it) with sunroof and metallic paint, pushing the price just north of $50,000.
Moving right along to the second portion of the challenge, the slalom. Piece of cake, I though.
Well, the damp circuit and camber of the corner meant that watching your p’s and q’s was entirely necessary, otherwise all 350Nm of the 120d’s turbo-diesel would hit at once, resulting in masses of oversteer!
While fuel consumption was not recorded during the slalom, we got to feel what the car was like when pushed to its limits through tight corners and sudden direction changes, as simulated by the slalom.
The lack of body roll and emphasis on steering precision made the slalom quite a challenging task, especially with the damp circuit.
BMW’s claims of 4.8L/100km (combined) were easily achieved by all journalists on the drive down to the track. This impressive fuel economy figure is thanks to a few features BMW use exclusively on its Efficient Dynamics vehicles.
The list includes:
- Air Vent Control: Air vents will open as required by the drive, but will remain closed in situations where air circulation is not required, thus reducing fuel consumption by some 0.7 per cent.
- Optimum Shift Indicator: This featured suggests when the drive should change gears (either up or down) to remain in the optimum fuel efficiency zone.
- Electric Power Steering: Although it’s relatively self explanatory, the electric power steering uses an electric system opposed to the regular hydraulic system.
- Brake Energy Regeneration: Similar to the way a hybrid charges its batteries, this system allows the 120d to recharge the car battery in order to put less strain on the alternator, which requires engine power to operate.
- Auto Stop/Start Function: This feature automatically switches the car off when it becomes stationary. Similar to the system used in the Land Rover Freelander2 TD4.e we tested this week, it saves fuel by not running the engine while the car is stationary.
The most enjoyable part of the day had to be the motorkana circuit, which tested the driver’s ability to judge the car’s dimensions, passing through gates and lane change cones. After the gates, drivers had another slalom and then a u-turn bay which required vigorous use of the hand-brake!
While I have complained about BMW’s Dynamic Traction Control (DTC) mode in the past, it proved to be the pick of the driver aids during the motorkana. The system limits the intervention of the Dynamic Stability Control (DSC) and gives the drive more freedom with regards to the level of play before the system intervenes.
This meant plenty of tail out action and little system intervention, but it was still there in the event things went pear shaped!
Finally, before the day was out, it was a drive back to BMW’s Mulgrave headquarters from Phillip Island GP Circuit via the regular highway route. This time around the challenge was strictly to use as little fuel as possible.
Once the car has momentum, it’s frugal and simple to keep it moving, even when climbing hills. Sixth gear has long legs and really moves the car along whenever you dab the accelerator.
Highway cruising had the trip computer reading instantaneous fuel consumption of around 3.8L/100km on flat surfaces. It would then jump to around 10L/100km on hills and back to 0 when coasting.
While I rolled into the last set of traffic lights before turning into BMW’s headquarters with the average fuel consumption reading 4.1L/100km, the move from stationary nudged it back to 4.2L/100km, which is still an extremely commendable figure.
By my calculations, the trip to Phillip Island and back took around 274km. While the car averaged around 4.3L/100km there and back, we used a total of around 11.782-litres. With diesel currently at $1.19 a litre, the trip cost $14 – not bad, eh?
BMW’s 120d is currently in showrooms with the remaining onslaught of its Efficient Dynamics range arriving by early next year.
It wouldn’t be serious without some good old fashioned competition though, so I’ll let you know on Saturday how I ended up fairing against the rest of the journalists.
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