“Less fuel, more performance”, this was the opening line at the presentation of BMW’s new eco-friendly 5 Series – the Active Hybrid 5. BMW is well known for its efforts to improve fuel consumption and lower CO2 outputs under the banner of EfficientDynamics. While such endeavours are laudable, there comes a point where a company has to take the next step towards eco-friendly motoring, beyond improving combustion. Aerodynamics and reducing weight is not enough – hybrid technology is the next step.
The Active Hybrid 5 is essentially a BMW 535i (3,0-litre, 225kW, turbopetrol) coupled with a 1,35 kW.h lithium-ion battery pack in the boot, a 40 kW electric motor in the bellhousing of the eight-speed automatic gearbox and some additional control software. Styling-wise the vehicle is difficult to differentiate from its non-hybrid stablemates, but the keen eye will quickly spot the “hybrid” logo on the rear and slightly more pronounced badging on the C-pillars. An optional lightweight alloy wheel was also developed to enhance the efficiency of the package.
Climbing into the vehicle you are greeted with the now familiar upmarket 5 Series interior. The central display has a few extra menu options to show the workings of the hybrid drive in a graphical representation, as well as the driver’s instantaneous and historic fuel consumption data. The climate control system can run on the high-voltage battery power alone when the petrol engine is stopped. Starting the car involves pressing the start button on the dash with only the instrument cluster lighting up to suggest that the vehicle is ready to go. By carefully applying the accelerator pedal the vehicle can be driven for approximately four kilometres at speeds up to 60 km/h on battery power alone.
During normal driving the petrol motor does most of the work but can be assisted by the electric motor under acceleration – BMW calls this “electric boost”. Kinetic energy is recovered by the system during braking and stored by charging the battery pack. Another strategy employed in the quest for lower fuel consumption is “sailing”, where the petrol engine will de-couple from the drive train and switch off when the vehicle has reached a steady-state condition, for example cruising downhill. The standard satellite navigation system is cleverly used as an input to the control algorithms that factor in the typography of the route selected. Stop/start technology is also employed to eke a few more kilometres out of the fuel tank.
Although the vehicle is about 100 kg heavier than the non-hybrid version, the performance is on par (even slightly better under certain circumstances) due to the electric assist enabling a 0-100 km/h time of 5,9 seconds. A quick blast up Helshoogte pass outside Stellenbosch in sport mode confirmed this. Apart from the graphical display, the driver is mostly unaware of the hybrid actions taking place while driving. Claimed fuel consumption is an amazing 6,4-7,0 L/100 km on the European drive cycle depending on the tyre choice. We could only manage 8,6 L/100km during our mostly leisurely drive of around 200 km.
This brings us to the next question: Who will buy the Active Hybrid 5? While it’s certainly more efficient than the non-hybrid 535i but consumption is still higher than the most efficient diesel option. According to BMW’s marketing folk, some environmentally conscious individuals like to drive petrol-engined vehicles and are not interested in diesel powertrains. Another consideration to the purchaser will have to be long-term ownership proposition. Although the battery pack warranty period spans five years, the replacement cost is a hefty R52 000, should it go wrong after the warranty has expired.
During our test drive a small glitch in the car’s ESC system sounded several alarms in the instrument cluster and only went away after stopping and re-starting the vehicle. Although this could have happened to any vehicle and was not hybrid-related, it drove the fact home that the more technologically advanced modern cars become, there is, unfortunately, the greater the risk of something going wrong.
The BMW Active Hybrid 5 is the first of three Bavarian hybrids coming to South Africa. The 3 and 7 Series models will be launched towards the end of the year. If you are looking for a sporty, luxury sedan with green credentials then the Active Hybrid 5 might just be your kind of car.
Model: BMW Active Hybrid 5
Engine: 3,0-litre turbopetrol/synchronous electric motor
Power: 225 kW (engine), 40 kW (electric motor), 250 kW combined
Torque: 400 N.m (engine), 210 N.m (electric motor), 450 N.m combined
0 to 100 km/h: 5,9 sec
Top speed: 250 km/h
Fuel consumption: 6,4 – 7,0 L/100 km (European cycle depending on tyre choice)
CO2: 149 – 160 g/km
Price: R757 300