Luxury limousine is more about effortless performance than saving fuel and money.
Anyone who can afford a $222,000 luxury sedan is unlikely to care about saving $4 a week on fuel. But high-end consumers will see value in the new 7-Series ActiveHybrid's whisper-quiet motoring and welcome the performance boost of its electric motor.
The ActiveHybrid 7 will become BMW's third petrol-electric model when it arrives in Australia in March 2013. It joins the 5-Series-based ActiveHybrid 5, which landed in October, and the smaller ActiveHybrid 3, due this month. All three combine an in-line six-cylinder petrol engine with an electrically-driven motor to deliver an economy and performance boost.
Typically, new technologies debut in the most expensive models. But hybrid technology, first seen more than a decade ago in much cheaper cars from Honda and Toyota, has been slow to reach these flagships, suggesting luxury consumers aren't as concerned with saving fuel.
BMW claims the ActiveHybrid 7 uses 1.1 litres per 100km less than its petrol-only equivalent (6.8 v 7.9). And although it has more power and torque, the hybrid's 150kg additional weight (mostly the battery pack which takes up space in the boot) means it accelerates from zero to 100km/h in the same 5.7 seconds.
As we glide at a stately 50km/h through a sleepy German town south of Munich, the petrol engine shuts off completely, leaving the lithium ion battery to power the car's movement via an electric motor.
On its own, the electric motor generates 40kW of power, less than half a Corolla, but it's enough to maintain the two-tonne sedan's momentum and gently accelerate. This engine-less driving takes luxury sedan refinement to new extremes; the only sound is the barely perceptible rumble of tyres on the smooth European road surface.
Emerging into the countryside, our speed increases and the petrol engine takes over completely, recharging the battery by capturing potential energy whenever I brake. The road climbs and I give the accelerator a determined push.
The electric motor returns, this time in the role of a power-booster, complementing the petrol engine's 235kW and 450Nm outputs to deliver a combined 260kW of power and 500Nm of torque.
The big 7-Series charges strongly up the incline, building speed with ease. The electric motor's innate ability to generate pulling power at low revs means strong, syrupy performance that suits the 7's reputation for easy, hassle-free driving.
During the course of the day, we drove more than 300km at speeds between 50km/h and 250km/h on autobahns and in the Austrian Alps. Four-up and loaded with luggage, fuel consumption averaged 11.2L/100km, far from BMW's 6.8 litre claim, although more than acceptable under the extreme circumstances.
The ActiveHybrid 7 will become the sixth of BMW's flagship 7-Series models, priced at $11,000 more than the petrol-only BMW 740i. It delivers refined, effortless motoring with a green tinge and a BMW badge.
But its biggest marketplace challenge may come from within. The 7-Series turbo diesel 730d has commensurate performance and uses 1.2L/100km less fuel – and is $7000 cheaper. It all depends on how keen luxury consumers are to save a dollar or two.