Crankandpiston’s latest jaunt to Portugal for the Mini Coupe Roadster launch (more of which to come) didn’t go entirely without problems. In one afternoon I managed to misplace my camera, turn up at a different hotel to my luggage, and lock myself out of my room. Clearly some drive time was required to wash away these woes, so I got on the phone to my BMW hosts and within 30 minutes was holding the keys to the company’s latest ActiveHybrid 5-Series.

I know what you’re thinking: “A hybrid? Come now, that’s hardly crankandpiston fodder!” Let’s be fair, we took a tentative spin in the Tesla Roadster recently and that turned out to be a hoot. Why not BMW’s flagship executive saloon?

Though equipped to provide the luxury and exuberance of previous 5-series models, the ActiveHybrid definitely has low fuel consumption in its sights. Intrigued, I get myself seated, nod studiously as I’m shown the ins and outs, and fire the Beemer into life: “are you sure it’s on?”

Grabbing the bull by its corked horns, we begin the drive in full Eco Pro mode, where everything runs on the lithium-ion battery. Alarming as the rev counter plummeting to zero is, watching the blue battery and red engine mapping alternate on the powertrain display is strangely entertaining. Our traffic-related 10kph average speed means that it’s only at the city limits when the exhaust notes make themselves heard, which is a little unnerving. Though we can feel the power subside when stop-start kicks in at standstill, it is not quite as obvious on start-up, which erodes confidence significantly when entering a busy junction.

So far, so frugal. Finally onto the auto-estrada, we flick the mode button up once to activate Comfort Plus. The change between modes is extraordinary. The lethargic throttle response in Eco Pro has all but vanished, and though this new-found acceleration is hardly cricking our necks, still we can’t help marveling at this new found ‘performance’. Blue slips to red immediately, but once up to speed, we are still saving enough energy to re-charge what battery power we’ve used negotiating city traffic.

Twenty clicks and a tollgate further down the motorway, we pull off in the direction of green hills and winding roads. Selecting a route from our veritable pick-and-mix, we flick into Sport mode to put this low emission beast through its paces. Again, suddenly we’re driving a different car.

The whole car hunkers down, the steering becomes weightier, speed is delivered instantly with the smallest flick of the ankle, and scrubbed off just as quickly. Paddle shift gear changes are swifter, more linear. And if we forget to change up, we’re well into the redline before the automotive transmission kicks in. Though sat-nav directions kick gear selection off the head-up display, current pace and speed limits are clear to see on the windscreen front and centre. Several swooping corners in, we try our luck in Sport Plus into the next corner.

Slow in, full lock right and a bootful, and the rear gracefully steps out with muted tyre squeal. Suddenly this executive saloon feels nimble and lithe, the traction-control ‘off’ light telling us it won’t be held responsible if we bin it. Then again, awesome amounts of grip and feathering the throttle when we go too deep means there’s little fear of that. Back in Comfort mode, the car is more responsive than it has any right to be on these roads, even re-charging the battery when it can.

Several hours of general larking around pass, as do dozens of petrol stations. Back at the hotel, the keys are returned to their keepers. Raiding the minibar, we ponder – given the opportunity – which other parts of Portugal we’d rather tour in the ActiveHybrid 5: frugal city streets, or piston pumping country roads. Our choice probably won’t surprise you >>>