Click, click, click goes the sound of the start button of the BMW ActiveHybrid 5 as my impatient finger repeatedly pushes it in. Rather than the expected resounding thrum of an engine, the cabin is filled by a deafening silence as the instrument needles sweep across the illuminated dials. Yip, this BMW has a silent start-up that is a strange and somewhat disconcerting experience, especially when pulling away from a standstill. The BMW ActiveHybrid 5 marks the first of three hybrid models to be introduced by BMW South Africa – 3 and 7 Series hybrids will follow sometime next year. Get over the initial anxiety of driving silently and you will comfortably cruise emission-free for four kilometres at a maximum speed of 60kph before the battery drains or an aggressive throttle input forces the petrol engine to come to life.
The car employs the familiar 225kW/400Nm 3.0-litre six-cylinder turbocharged engine from the 535i with the addition of a high-voltage lithium-ion battery pack that supplies a 40kW electric motor with sustenance.The battery pack is positioned inside the boot marginally lowering boot volume while the electric motor resides in the bell housing of the eight-speed automatic transmission. The electric motor supplements the petrol engine with an additional 25kW and 50Nm for a combined power output of 250kW and 450Nm. So it’s fast then? Of course. With Sport-Plus selected the Hybrid 5 will accelerate from zero to 100kph in 5.9 seconds before reaching a limited top speed of 250kph – that’s 0.2 seconds quicker than the 535i.
However, hybrid motoring is all about green credentials and the ActiveHybrid is mighty impressive in this regard. Driven conservatively BMW claim a combined fuel consumption read out of 6.4l/100km and an emission figure of 149g/km. Driven hard we managed an astounding 9l/100km, which gives you an idea of just how frugal the hybrid set-up is. The ActiveHybrid 5 boasts a raft of clever fuel-saving techniques such as a hybrid start-stop function and a regenerative braking system that recharges the battery pack. It also features a coasting mode which boosts efficiency by switching off and decoupling the internal combustion engine from the drivetrain when the vehicle is stationary or coasting at speeds of up to 160kph. Dynamically the Hybrid 5 is just as capable as any other BMW dispatching corners with the same level of composure as its 535i sibling. Visually it can be told apart from other 5 Series models by several bespoke touches which include galvanised kidney grille slats, matte-chrome exhaust tailpipes, ActiveHybrid5 lettering on the C-pillars and door sills, exclusive Bluewater metallic paint and 18-inch optional alloy wheels.
Inside, the only notable difference is the ActiveHybrid 5-branded aluminium plate on the centre console. The 9.2-inch iDrive screen is a great piece of kit which along with displaying the navigational map also features integral vehicle information such as the hybrid powertrain monitoring system. The ActiveHybrid 5 may be the most powerful and efficient full hybrid on the market but careful examination of the current 5 Series range will reveal that the marginally more expensive 535d is, in fact, a greener proposition. It’s more powerful (230kW/630Nm), more economic (5.6l/100km) and less polluting (148g/km) than the hybrid model. BMW plan on bringing just 30 units to SA as a means to gauge whether there’s any local interest. Either way it’s going to be pretty interesting to see how many of them find homes in relation to the impressive 535d.