BMW ActiveHybrid 5 !

After having us over to drive its raging new M5 last September, BMW is now aiming to show just how efficient their F10 5 Series can be with the occasionally silent and rage-free ActiveHybrid 5. Whereas the ActiveHybrid X6 and ActiveHybrid 750i arrived somewhat lacking in state-of-the-art hybrid credentials, the ActiveHybrid 5 carries a true and undeniable full parallel hybrid powertrain starting with all the goodness you find in a 535i.

This ActiveHybrid 5 is essentially a 535i sedan that pollutes less, travels farther on each of its 17.7 gallons of fuel, is painted BMW's alternative-propulsion color of choice, Bluewater Metallic, and weighs 330 pounds more due to its electric motor, electric power unit motherboard and lithium-ion battery pack. Both CO2 emissions and range are said to improve by roughly 16 percent in a car that performs up to par with a 535i, so it's a likeable proposition. Sticking with the standard 17-inch wheel/tire setup and setting the Driving Dynamics Control to Eco Pro mode, that'd make the CO2 rate 240 grams per mile – an impressive stat that most Americans still don't care about – and an average EPA city/hwy combined fuel economy score of around 31 miles per gallon. 

With a base price of $61,845, the ActiveHybrid 5 will cost 17.8 percent more than the $52,500 535i when it arrives at U.S. dealers in late March. For comparison's sake, the ActiveHybrid 750i costs 15.1 percent more than the 750i and the recently discontinued ActiveHybrid X6 ran a whopping 26.8 percent more than the X6 xDrive50i.

Hop in, press the Start button, and there is the passionate sound of silence. Digital dials light up, bright needles bounce right then back to the left, and there is some subtle whirring that goes on originating from the EPU somewhere deep beneath the driver's seat. That's the ActiveHybrid 5 booting up.

If we hadn't been driving the ActiveHybrid 5 over a highly dynamic route in Portugal with lots of coastal hills, maybe the car could have stayed in eDrive mode all the way up to BMW's stated electric-only top speed of 37 mph. But the road bent upward right out of the parking area, and the somewhat adapted N55 TwinPower Turbo 3.0-liter six-cylinder came on-line after only a few hundred yards of travel.

Naturally, the system's usefulness depends on exactly how much of this detailed topographic and infrastructure information has been made available by various federal and state entities. It's no coincidence that this information is now readily available in Germany – right down to small dirt farm roads. The U.S., however, has a ways to go, as you might imagine. In fact, there's a ways yet to go on IEM mapping in Portugal, too, but this technology is still a first for production cars.

Given the wild up and down swings of the routes we drove, the best fuel economy we realized was 25.6 mpg, and that was while driving like the most tender-minded motorist in the Garden of Eden. This is respectable for a 4,420-pound (fluids and driver aboard) executive sedan under these road conditions. There were a few points along the route where we managed to find the delicate sweet spot of the accelerator pedal while in the DDC's Eco Pro mode, and we were able to coast with the internal combustion engine decoupled – essentially eDrive – at speeds between 80 and 90 mph on rural highways. The limit for this is 100 mph and it is a worthwhile sensation to experience.

But how is any of this really better than the 4,145-pound, diesel-powered 535d with its 308 hp and 465 lb-ft of torque? The 535d averages equal or better real world mileage per gallon, emits a bit less CO2 per mile and, by our math, costs what would be around $5,000 less. Is this simply the finest efficient alternative for markets that by and large reject diesel?

Regardless, we all know that hybrids effectively are the American diesel market – and vice-versa in Europe – at least for the time being. We definitely like the ActiveHybrid 5 in the general sense; it's perhaps the finest execution of a high-end everyday driving hybrid that we've tried yet. But will it sell well enough to get us to shut up about BMW's remarkable diesels? If the general market impact realized by the previous two ActiveHybrid models is any indicator, forgive us if we aren't jumping out of our socks after staring at BMW's business case. We certainly tip our hats to Munich for their best hybrid yet, but the Germans have their eyes on owning another kind of green awareness that goes beyond hybrids.

Our suspicion is that BMW is using its ActiveHybrid models as something of a (admittedly quite capable) time-filler while the world waits for the launch of its ultra-efficient i3 and i8 models. In fact, we wouldn't be surprised if BMW knocks us out with a Super Bowl ad or two next year for these more significant and genuine efforts.