We are in a nondescript office in Munich. It's 2008 and talk turns to the development of the 2012 BMW ActiveHybrid 5. They're speaking German, but we have a translator on hand. "Toyota has achieved cult status with the Prius by combining an electric motor with a gasoline engine," says Luther. "We could team a four-cylinder turbo with our own motor and build the world's most efficient executive sedan."
"That is true," Wolfgang interjects, "or we could pair an electric motor with a 300-horsepower, six-cylinder turbo and make it bloody fast." Both men smile as one. They know only too well that in the market of the future, customers won't want a hair-shirted alternative; they'll want a high-performance sedan with a feel-good badge. "We'll call it Efficient Dynamics," says Wolfgang, "but with the focus on the Dynamics."
And thus, from a gray office in Bavaria, the ActiveHybrid 5 was born. Allegedly.
Fast-forward four years and on a chilly day in Lisbon, Portugal, we're confronted with the reality of the 2012 BMW ActiveHybrid 5. BMW knows that hybrid buyers like to shout about their purchase, even if it's only used as a shuttle to a private airport. That's why there are giant "look at me" ActiveHybrid badges on the C-pillars, and more on the trunk. There's a revised kidney grille with "galvanized slats" and the option of some proprietary 18-inch wheels which, according to BMW, "display exceptional aerodynamic efficiency." Most customers are also likely to opt for a Bluewater Metallic paint job, which is unique to BMW's hybrid range. Combine all this and no one will doubt that you genuinely care and are nothing like those socially irresponsible types in the 550i.
Slide a sandal inside and you'll be greeted by more conscience-pleasing paraphernalia. This includes "ActiveHybrid 5" door sill strips and a little aluminum plaque on the center console. The 9.2-inch color display system also boasts a few new functions. There's a neat graphic that tells you how the energy's being distributed and a bar chart that tracks your fuel consumption over time. The latter offers the opportunity for a bit of sport, although we also found it inspired a masochistic tendency to score as poorly as possible.
The rest of the cabin is classic 5 Series, which is no bad thing. It's true that the 5 looks like a scaled-down facsimile of a 7 Series, but that's more likely to worry owners of the top-line model. The quality is tremendous, with the exception of some nasty plastic on the internal B-pillar, and the driving position is made perfect by a steering wheel that offers an exceptionally long range of telescopic adjustment. This means you can adapt the NASCAR position, even if you're long of leg.
As with nearly every contemporary BMW, a drive of the ActiveHybrid 5 cannot be undertaken without first engaging in a little computer science. The default setting for the Driving Dynamics Control is Comfort, in which mode the hybrid is almost indistinguishable from the mainstream models. If you want to experience the full benefits of gas-electric propulsion, you need to activate Eco Pro mode. Only now will you feel like you're driving a hybrid.
In essence, the 2012 BMW ActiveHybrid 5 is a 535i with an electric motor assistant. The motor is integrated into the transmission, while the lithium-ion battery pack is housed in the trunk, just behind the rear seats. It pinches a not inconsiderable 5.1 cubic feet of space, which leaves 13.2 cubic feet. The system weighs 309 pounds, which partly negates the benefit of electric propulsion.
On its own, the electric motor serves up 54 horsepower and 155 pound-feet of torque, while the 2,979cc turbo inline-6 offers 306 hp and 295 lb-ft. Put the two together and transmission losses reduce the combined sum to 335 hp and 330 lb-ft of torque in a vehicle that tips the scales at 4,079 pounds (EU measure). The weight-to-power of 12.2 pounds per horsepower is better than a 535i, but not by much.
Assuming there's power in the battery and you've bothered to select Eco Pro mode, the ActiveHybrid can be driven at speeds up to 37 mph on electric power alone. But not very far: BMW reckons you can drive 2.5 miles at an average of 22 mph before the gasoline engine must intervene. Keeping it in electric mode also means playing footsie with the throttle or you'll inadvertently kick-start the engine. If you're dawdling in L.A. rush-hour traffic, then the system has an important role to play, but if you're a country boy, it's hard to see the benefit.
The car's eco-credentials may at times feel a little tenuous, but there's no denying its rapidity. A big dollop of instantaneous torque from the electric motor helps propel the 5 from zero to 62 mph in just 5.9 seconds, according to BMW's own figures. In the midrange it's properly quick and a genuine sleeper. The near-silent operation of the electric motor, coupled with the refinement of the engine lends the car a stealthlike quality. You tend to be traveling faster than you think, a phenomenon it shares with the ActiveHybrid 7.
The eight-speed ZF gearbox also has little trouble marrying the power sources. Whether in full auto or when using the sequential paddle shifters, it's unerringly smooth. Indeed, the downchanges are some of the best we've experienced from any type of 'box. The reengagement of the engine is similarly impressive. The starts and stops are almost imperceptible from the cabin.
The rest of the driving experience is familiar 5 Series. The ride is excellent and there's no denying its ability to cover ground at high speed in supreme comfort, but some of the sporting edge that characterized 5 Series of old is missing. The steering is the biggest culprit. Not even BMW has come close to developing an electrically assisted system that matches the feel and sensitivity of the old hydraulic setup. As we've found with our long-term 528i, the modern 5 Series is a brilliant everyday tool, but the days when a base model could also pose as a weekend plaything are over for now.
The role of the 2012 BMW ActiveHybrid 5, of course, is to combine the performance of a V8 with the economy of a six, and it's packed with fuel-saving tech. A start-stop function automatically shuts down the engine when the car is at rest. There's also a coasting function, which decouples and shuts down the gasoline engine at speeds up to 100 mph in Eco Pro mode, or 50 mph in all other modes. This is increasingly common — Porsche, for example, already offers a similar system in the Panamera and new 911 — and is designed to make the best use of "free" kinetic energy already available.
More unusual is BMW's use of the standard navigation system. Assuming it has sufficient data, the system can analyze the terrain and set the car up accordingly. For example, if it identifies that a sharp uphill is followed by a long descent, it will happily use all the battery power on the way up, knowing that it will be replenished. It's clever, but its success depends on the quality and quantity of the navigation data, which is far from consistent.
There are no EPA figures yet for the ActiveHybrid 5, but one can learn something about its efficiency by studying the European figures. These reveal an average (using EU regulation but U.S. gallons) of 36.7 mpg for the hybrid, compared with 29 mpg for a 535i and 22.7 mpg for a 550i. It also produces 149 g/km of carbon dioxide, which is 36 g/km or 19 percent less than the 535i. How these figures will translate to EPA ratings remains to be seen, but our experience suggests the real-world benefits of hybridization rarely match the benefits described on paper.
It should also be noted that these figures are for an ActiveHybrid on 17-inch rims. Opt for 18-, 19- or 20-inch alloys as most owners surely will and the combined consumption figures drops to 33.6 mpg.
The ActiveHybrid's real role in life is to serve as a poster boy for BMW's EfficientDynamics program, at least until the i3 and i8 arrive. BMW admits that it's likely to account for less than 5 percent of 5 Series sales in the U.S. and that many customers will choose it as much for what it says as what it does.
Those who look beyond the marketing bluster, though, will find a highly capable and extremely rapid executive express. It's a fine car, but whether the marginal economy and performance benefits over a 330-hp 535i can justify a hefty price premium is open to debate. At $61,845 the ActiveHybrid costs almost $10K more than a 535i and about a grand less than a 400-hp 550i.
This remains the great conundrum of hybrid ownership. The 2012 BMW ActiveHybrid 5 may be an important pointer to the future, but right now we struggle to recommend it over a regular 535i.
Edmunds attended a manufacturer-sponsored press event to facilitate this report.