Porsche has further extended its hybrid strategy with a petrol-electric version of its four-door, four-seater Panamera grand tourer.
The Panamera S Hybrid joins the Cayenne Hybrid SUV to beef up the German sports car maker's alternative drivetrain line-up in Australia.
On sale now and arriving at dealerships in August, it will be powered by a supercharged V6 engine making 245kW from 5500 to 6500rpm, and 440Nm from 3300 to 5250rpm.
It is supplemented by a parallel electric motor making 34kW and 300Nm from as low as 1150rpm. When the two outputs are overlaid, the Panamera S Hybrid can summon 279kW at 5500rpm and 580Nm at just 1000rpm. Together, the two motors can propel the Panamera S Hybrid to 100km/h in 6.0 seconds, on the way to a top speed of 270km/h.
The two engines are mated to an eight-speed "Tiptronic S" automatic transmission first seen in Australia last year on the Cayenne, with six conventional gears and two overdrive ratios, which Porsche says can reduce shift times by as much as 50 per cent over conventional autos.
The rear-wheel-driven Panamera S Hybrid is also fitted with an engine stop-start system that switches the engine off when the car comes to a stop.
It's the second-most economical model Porsche has ever built (behind the Panamera diesel) with a combined fuel use of 6.8 litres per 1000km, when fitted with optional low rolling resistance tyres. Without them, its 7.1L/100km falls just shy of satisying the federal government's 7.0L/100km economy target that allows it to qualify for a significant tax exemption.
With CO2 emissions of 159 grams per kilometre (on the optional "green" tyres), the big Porsche releases less greenhouse gas than a Toyota Corolla.
An 80-litre fuel tank gives the Porsche grand tourer a theoretical range of 1470km, albeit on diet of premium (95 RON) unleaded petrol.
The near-two-tonne car can drive on electric power alone for up to two kilometres, and can "sail" - drive at a constant speed on a flat road - at speeds of up to 165km/h without needing to engage the petrol-powered V6 engine.
Pressing the "E-Power" button blunts throttle reponse and delays introduction of the petrol engine, with the car's abundant electrically-supplied torque reserves stepping in to supply required acceleration.
However, quick bursts of acceleration can still be summoned in normal mode, with a "boost" mode combining the power of the two engines to unleash full power for short periods.
Equipment levels on the Panamera S Hybrid line up closely with the V8-powered Panamera S model, which includes Porsche's adaptive damping control system that enables the driver to choose comfort, sport or sport-plus settings, adaptive air suspension, and electrically-assisted power steering that becomes firmer as speeds rise.
Inside, the seats are finished in partial leather, with the front pews heated with 14-way electric adjustment. The two rear seats are separated by a foldable centre armrest. Also standard are dual-zone climate control, front and rear parking sensors with a reversing camera, a sunroof, and a seven-inch central touch screen housing satellite navigation and various multimedia functions including Bluetooth.
A plethora of options include a choice of numerous interior finishes, quad-zone climate control, a new lane change assist system and an upmarket Burmester sound system.
The battery pack - consisting of 240 lithium-ion cells and weighing about 70 kilograms - sits beneath the boot floor. Some components that previously sat under the floor have been moved to fill spaces either side of the boot, stealing a total of 110 litres of boot space compared with the Panamera S. Boot space is a modest 335 litres, increasing to 1153 litres when the rear seats are folded.
The Panamera S Hybrid starts from $298,300 fitted with standard 19-inch wheels and tyres. However, spending an extra $290 to add low rolling-resistance tyres generates fue savings that push the car into the sweet spot for a luxury car tax exemption, slashing the price to $292,927 - a saving of $5083. Porsche expects the majority of its Australian customers will opt for the "green" Michelin tyres.