MUNICH—If Kermit the Frog were to get his fuzzy derriere behind the wheel of a 2013 BMW ActiveHybrid 3, he would likely start singing, “It’s not tardy being green.”

And possibly a few choruses of “Sailing” by Christopher Cross. More on that later.

When it comes to gas/electric hybrid vehicles, there are two approaches. The Toyota Prius uses every possible technological nuance to extract maximum fuel economy, resulting in a very frugal and equally bland motoring experience. Conversely, the hybrid BMW 3 sedan uses electric assist as much for maintaining its performance image as it does for the reduction of fuel consumption.

Conventional wisdom would have BMW hybridizing its already efficient turbo-four 328i sport compact sedan, but here we see the potent 335i with its TwinPower turbo 3.0 L inline six-cylinder getting the hybrid treatment.

When Kermie puts his flipper down, this conservative-looking four-door will zip to 100 km/h in a scant 5.3 seconds, thanks to its 335 hp and 332 lb.-ft. of torque. That’s an increase of 13 and 11 per cent respectively over the gasoline-powered 335i.

Another notable increase is price. The hybrid sees a list of $58,300 versus $51,200 for the comparably equipped gas version.

So what do we get for our $7,200? Another 135 kg in mass, a whole raft of cool technology, a marginal gain in fuel economy and a presumably clearer conscience.

The hybrid is rated at 5.9 L/100 km highway and 8.0 L/100 km city. The 335i sedan on which it is based matches the highway number at 5.9 and is not far off the city figure at 9.1. Sure it’s something, but certainly not enough to have the polar bears high-fiving.

BMW is betting there are customers who will pay a premium for a six-cylinder 3 Series that will hum about the ’hood for up to 4 kilometers on electric power, as well as do the things expected of a sports sedan.

Negotiating the smooth and winding roads of rural Bavaria, the ActiveHybrid 3 was quite at home, unravelling the black ribbons with uncanny swiftness and poise. The eight-speed auto shifts smoothly and responds quickly to shift paddle inputs, if you are so inclined. The seats are superb and the thick-rimmed wheel meaty in the palms.

A few brief Autobahn blasts showed the car to be rock solid at more than double our national speed limit.

A toggle switch on the console calls up three driving modes (Eco Pro, Comfort, Sport) with each adjusting the parameters of shift function, steering feel, throttle response and the adjustable dampers.

Aside from the lithium-ion battery pack that lives between the rear-wheel arches, all the interesting hybrid bits are in the transmission. In place of the usual torque-converter is an electric motor/generator that makes 55 hp and 155 lb.-ft.

Getting back to my earlier “sailing” reference, when lifting off the accelerator while coasting or going downhill in Eco Pro mode, the engine decouples from the drivetrain and shuts off at speeds up to 160 km/h. The only thing weirder that flying along at 120 km/h with the tachometer needle resting at zero is how instant and absolutely undetectable this transition is.

The battery pack is mainly charged during coasting and braking, and, as with all hybrids, there is an auto start/stop function.

When we slowed to cruise through the many hamlets dotting the countryside, the BMW usually remained in full EV (electric) mode.

A fascinating “first” technology links the hybrid management electronics to the navigation. By reading the topography of the planned route, the car anticipates the drivetrain power flow and regeneration periods, somehow making the whole process more efficient.

What my driving partner and I both noticed was a slight gruffness to the inline-six that wasn’t noticeable in the non-hybrid BMW models we drove fitted with the same N55 single twin-scroll turbo engine.

Although many hybrid sedans lose significant luggage space to the battery pack, BMW has kept this to a minimum. Trunk volume is down by just 10 litres and the 40/20/40 folding rear bench with pass-through remains.

At the end of the day, we saw 9.1 L/100 km on the car’s computer. If you’re thinking, “Holy cow, that’s a lot of trouble to go through to eke out a few more L/100 km,” well, welcome to the electrification of the automobile.

To play the devil’s advocate here, a few years ago, I drove the fabulously swift previous-generation 335d diesel 3 Series (no longer available in Canada) over the same roads and saw 8.3 L/100 km.

And there are diesel versions of this new-gen 3 Series in Europe that put the ActiveHybrid 3 to shame when it comes to fuel economy, but for reasons too numerous to mention, we’ll see them in Canada when Miss Piggy flies.

The AvtiveHybrid 3 was developed mainly for the strong gasoline markets of the U.S. and Asia. As project leader Dr. Herbert Negele said, “Our clear target was to build the BMW of hybrids.” On that count, they seem to have succeeded.

2013 BMW ActiveHybrid 3

PRICE: $58,300, base; $61,800 as tested

ENGINE: 3.0 L TwinPower Turbo inline-six with synchronous electric motor.

POWER/TORQUE: 335 hp/332 lb.-ft.

FUEL CONSUMPTION L/100 km: 8.0 city, 5.9 highway

COMPETITION: Lexus GS 450h

WHAT’S BEST: drives like a 335i, cool tech, improved fuel economy.

WHAT’S WORST: pricey, heavier.

WHAT’S INTERESTING: battery pack gives car 50/50 weight distribution.