BMW Active Hybrid 5: Pointing to a greener motoring future
- Deon Schoeman
- Life, etc
- 07 Jun 2012 07:15 (South Africa)
Hybrid cars are supposed to be efficient, economical and environmentally friendly. But they’re often compromised as far as space, styling and dynamics are concerned. BMW believes its Active Hybrid 5 offers all the benefits of hybrid technology, but without any of the drawbacks. By DEON SCHOEMAN.
Like all vehicle manufacturers, BMW is under increasing pressure to reduce the fuel consumption and CO2 emissions of its cars to reduce their environmental impact. While all-electric cars and hydrogen power are still some way off, hybrid drivetrains appear to offer a suitable interim solution.
Considering BMW’s reputation for creating cars that link luxury to driving pleasure, it stands to reason that the brand wants its hybrid models to offer the same hallmarks. The problem is that hybrids have a reputation for compromised dynamics.
Hybrid cars combine a conventional petrol or turbodiesel engine with an electric motor and a battery pack. The real trick, however, is to provide a control system that optimises the interaction between the two power units to allow meaningful operation in a variety of conditions.
In the case of the BMW Active Hybrid 5, the control system is key to the hybrid sedan’s success. It ensures that operation is utterly seamless.
Accelerate hard, and the system summons the electric motor and the petrol engine to combine forces, thereby delivering maximum surge. Under trailing throttle, or when braking or coasting, the electric motor becomes a generator that charges the Active 5’s battery lithium-ion battery pack.
If there’s enough charge in the battery, the Active Hybrid can even run in zero-emission, all-electric mode, albeit at speeds of less than 60km/h, and over a limited distance only.
But you’d be hard-pressed to tell the difference between this 5 and its closest petrol-only relative, the 535i – an athletic sports sedan with a talent for rapid and involving motoring.
The exterior treatment is pure, F10-generation 5-Series, too: the chiselled, purposeful shape is identical to the petrol-only version, except for some rather garish badging on the bootlid and the C-pillars. In Europe, special aerodynamic wheels and narrower tyres contribute to even more frugal operation, but South African buyers get the standard rims and rubber.
Those familiar with the current Five will feel instantly at home in the Active Hybrid 5’s cabin. The driver-focused ergonomics are the same, the levels of luxury are equally comprehensive and the switchgear is identical, too.
Indeed, if it wasn’t for a diagram showing the mode of operation that can be called up on the car’s generous colour display, most drivers would never realise that they’d been behind the wheel of a Hybrid 5. The real differences are all under the skin.
The drivetrain of the Active Hybrid 5 combines a three-litre twin-scroll turbo petrol engine with an electric motor and an eight-speed automatic gearbox. The six-cylinder in-line engine is credited with 225kW and is coupled to an electric motor good for a further 40kW. The lithium-ion battery pack powering the electric motor is located in the boot, which has shrunk a little as a result.
With the petrol engine and the electric motor on song, the combined output on offer is 250kW. The system torque maximum comes to 450Nm.
If your previous experience of hybrid cars has been less than exciting in dynamic terms, the BMW Active Hybrid 5’s performance will come as a pleasant surprise. With the electric motor adding a further boost to the already muscular straight-six turbo engine, acceleration is indisputably sporty.
The zero to 100km/h sprint time of just 5.9sec places the big sedan squarely in the sports car league, while the top speed is governed to 250km/h. But the most impressive statistic of all is the fuel consumption.
BMW claims that the Active Hybrid 5 needs only 6.4-litres/100km for the combined cycle, and 6.7 litres on the open road. Utilising the all-electric mode in town as much as possible, urban consumption could even dip under the 6-litres/100km mark.
Driving on electric power only takes some getting used to, however. In fact, it’s downright disconcerting. There’s something eerie about piloting a dead-quiet car through busy urban traffic. It’s like gliding along in some futuristic capsule and, initially, you feel strangely disenfranchised.
Impressively, all the vehicle systems – lights, air-con, brakes, instruments, navigation – continue to operate as usual, despite a rev counter needle that’s parked at the zero mark.
But the electric-power-only range of the BMW is limited to around 4km – and only if you stick to speeds of 35km/h or so.
You also need to treat the accelerator with care: anything more than delicate right-foot inputs will be interpreted as a need for more surge, with the result that the turbo-six will take over the dynamic responsibilities.
Hybrid cars are nothing new in South Africa. Toyota’s Prius has been around for a good few years now, and was recently joined by a hybrid Auris hatchback. Lexus has an entire range of hybrids. No doubt, more hybrids from other brands will follow.
What the BMW Active Hybrid 5 proves more believably than any other hybrid at present, is that the combination of electric and combustion engine power, linked to advanced control systems, can provide a completely uncompromised motoring experience while offering very real environmental advantages.
Ironically, the new green machine’s toughest competition will come from within the BMW stable, rather than from other brands. The 530d costs R88 000 less, is only 0.1sec slower from 0-100km/h, sips even less fuel and has a lower exhaust emissions rating, too.
That said, cars like the BMW Active Hybrid 5 are trendsetters, allowing motoring manufacturers to showcase future technologies before they become part of the motoring mainstream, and to grow vital economies of scale in the process.
There is no doubt that the Active Hybrid 5, soon to be joined by the Active Hybrid 7 and the Active Hybrid 3, takes the hybrid motoring experience a further, important step forward. It’s a promising preview of a hybrid motoring future – and one that is sure to become more affordable as it is more widely adopted. DM
BMW Active Hybrid 5
Engine - 2,979cc six-cylinder turbo + electric motor
Gearbox - Eight-speed automatic
Combined power - 250kW @ 5,800rpm
Combined torque - 450Nm @ 1,200rpm
0 - 100km/h - 5.9 sec
Top speed - 250km/h (governed)
Fuel consumption - 6.4-litres/100 km
CO2 emissions - 149 g/km
Retail price - R757,300