By Lee Pang Seng
BMW has shown its ability to spread its engineering base and not put all its eggs in one basket by introducing hybrid cars. The German carmaker may see more merits in its diesel range to deliver power and mileage, but it too has to accept that diesel clatter is not widely accepted everywhere, such as China and the US.
Two models – ActiveHybrid 3 and 5 – were introduced here to reach out to those who prefer petrol power, but with a better fuel mileage range. Initially, these 3.0-litre hybrid cars did not come under the exemption on import duties put in place by the government, and commanded very premium prices at RM538,800 for the ActiveHybrid 3 and RM648,800 for the ActiveHybrid 5 (on the road without insurance but with BMW Service + Repair Inclusive). However, the Government has now included hybrid cars above 2.0-litre to be exempted and the prices have come down to RM398,800 and RM498,800 respectively.
These ActiveHybrids are not BMW’s first attempt at hybrid engineering. Earlier, it went into joint development with GM and Daimler to come up with a 4.4-litre V8 that was introduced in the 7 Series and X6. Subsequently, BMW decided to go it alone and settled for the smaller 3.0-litre unit that it is now using.
Dr Herbert Negele, the project manager for the ActiveHybrid 3, explains the rationale for the engine displacement: “With a big displacement engine, the improvement in fuel consumption is more clearly felt than with smaller displacement units. We feel this makes more sense to focus our hybrid development on bigger engines.”
Moreover, the choice of a 3.0-litre was to tap on an existing and winning engineering base as this platform had already won numerous awards and recognition for its smooth revving and efficient operating qualities. The in-line six-cylinder TwinPower Turbo develops 306bhp while the electric motor delivers 55bhp for a combined 340bhp. Transmission is the eight-speed automatic that is currently used across the BMW range of vehicles.
The results were up to expectation: the average fuel consumption was improved to 17km/l while performance is strong to stamp its BMW heritage. 0-100km/h is covered in 5.3 seconds and the top speed is electronically capped at 250km/h.
To allay fears of fires that could start during an accident, especially with the high electrical discharge from the huge battery, BMW conducted crash tests on the car and the battery itself to prove that such fiery outbursts will not happen. Dr Negele says the lithium-ion battery is developed and made in-house, and its lifespan is the same as that of the car at 10 years.
Although battery size for hybrid cars has generally been reduced considerably over the years, the BMW unit can fit in nicely into the standard 5 and 7 Series body, but not the 3 Series. This has led to a shallower boot as space is taken to accommodate the lithium-ion battery between the rear wheels. The ActiveHybrid 3’s boot capacity is reduced by 90 litres to 390 from the standard model.
Battery charging is done while braking and during coasting. The latter is made possible with the newly introduced ECO PRO mode that allows the car to coast (with the engine turned off in the ActiveHybrid case) on accelerator pedal lift-off.
We had the opportunity to have a go at the ActiveHybrid 3 (as well as being chauffeured around in the ActiveHybrid 5) during a visit last year to the BMW Driving Academy at Maisach, Germany. In all-electric mode, the top speed is 75km/h and the lithium-ion battery range is four kilometres at a constant 35km/h. A ‘test’ with the ActiveHybrid 5 (with battery level at 20 per cent) at the Driving Academy took us about 200 metres on electric power before the engine kicked in.
Our drive in the ActiveHybrid 3 took us through more than 100km of secondary roads and autobahns to the north of Munich. There was no lack of pace as we hit speeds up to 200km/h on the autobahn. The extra 136kg that the ActiveHybrid 3 carries over the standard model was not felt. And in urban traffic conditions, it behaved like a typical hybrid, with the engine switching off when coming to a stop and re-starting on brake pedal lift-off.
A noticeable difference over the hybrids we have driven so far, which were four-cylinder engine models, was the way the straight-six unit kicks in from electric mode. There was distinctly less shudder, unlike the mild jolt encountered with the four-cylinder hybrids. The in-line six engine allowed the transition to be smoothly engaged.
For the winding stretches, if we wanted more dynamic driving fun and selected Sport or Sport+ modes, the hybrid functions were disengaged. This allowed the ActiveHybrid 3 to run on full song and deliver the power and torque to take the corners confidently.
Driving in ECO PRO or Comfort modes, we enjoyed the coasting feature (which occurred at any speed up to 160km/h in ECO PRO and between 60 and 80km/h in the latter). The engine was shut off and disengaged from the driveshaft during this phase. We could see this as the tacho needle had fallen to zero. This helps to save fuel further, and is a feature that is also applied in the standard range.
At the end of the drive, we couldn’t tell if the ActiveHybrid 3 was more economical on fuel mileage without a direct comparison. What we could tell was that we had more than ample fuel when we returned the car. Maybe the fuel mileage gains were achieved during the urban drives, where a hybrid car would best serve its purpose.