The smog in Kuala Lumpur hangs like a muslin shroud as the morning sun casts its filtered rays across the bustling metropolis - a view we behold daily from a hill-top abode in the posh Cheras district.

But I am comforted by the fact that none of the atmospheric haze that lingers over our three-day visit can be attributed to the car we arrive in - the Porsche Cayenne S E-Hybrid.

The car is a plug-in petrol-electric hybrid, which is essentially a cross between a regular hybrid and a full- electric model.

With its 10.8kWh lithium-ion battery fully charged - a task accomplished in just three hours via a regular wall socket - the big sport utility vehicle can cover close to 30km without emitting a molecule of exhaust gas.

This makes it an ideal urban commute, just like its sibling, the Panamera E-Hybrid.

It is not a weedy commute either. Its 70kW electric motor produces 310Nm of instantaneous torque. Even for a vehicle weighing more than 2.3 tonnes (13 per cent more than a regular petrol-driven Cayenne S), it feels zippy on just battery mode.

The fringe benefit of this mode is comfort. With its supercharged 3litre V6 in suspended animation, the car is near silent and completely free of vibration. It glides unobtrusively along, blending in with the frenetic KL traffic with little ado - despite carrying four adults and their attendant luggage.

It remains energetic and moves effortlessly on hilly terrain that characterises the district, and its V6 comes to life only in the most demanding of circumstances.

In the city, it is not uncommon to see the trip computer posting a fuel consumption figure of 1 litre/ 100km. So Porsche's claimed economy of 3.4 litres/100km is quite believable - provided you plug the car in every time you get the chance to and you do not drive it like a madman.

The ability to go emission-free is augmented by the car's selfcharging cycle. But unlike conventional hybrids, you have to manually push a "charge" button on the dash to activate this cycle.

Unfortunately, I forget to do this on the North-South Highway, resorting later to plugging the car in when we arrive in Cheras.

On the highway, the electrified car is perpetually in combustion mode and it offers no economy advantage at all. In fact, it averages about 11.5 litres/100km - which is higher than expected for a cruiser equipped with a long-legged eight- speed transmission.

Then again, we are talking about a 2.3-tonne bruiser driven at close to twice the Singapore expressway limit over long stretches.

Despite its total output of 416bhp and 590Nm, the special Cayenne has a rather unresponsive throttle at times. You need to prod it hard to get meaningful acceleration. Thankfully, it is equipped with a far more responsive cruise control system.

On the highway, toggling between Resume and Cancel gives you the best driveability.

Like other variants in the current crop of Cayennes, the E-Hybrid is endowed with a capable and coherent chassis. Travelling at 110kmh in this car feels like 70kmh in a Japanese family sedan. Even at 160kmh around a long wide sweeper, you do not feel the need to shed speed.

The only niggle is that bit of judder that comes through the floorboard and steering column when you hold the brake pedal down firmly at high velocity. There is no hint of instability whatsoever, but the judder is palpable and a tad uncharacteristic of a high-end car.

That aside, the part-electric Cayenne is as likeable as its siblings, offering equal measures of luxury, comfort and versatility.

More than that, it is an engineering marvel that allows you to enjoy extreme ends of motoring - high- powered adrenaline-dripping jaunts on the highway and lowcarbon petunia-friendly trips to the supermarket and back.

Think of it as a Prius with a jet pack.