It is no surprise these days to see a new Porsche that looks very much like the one it has just replaced.

But the lack of outward change is always accompanied by a plethora of new technologies under the sheetmetal and the new Porsche 911 Turbo is no different.

From the outside, the latest iteration of the flagship 911 doesn't look dramatically different, but one telltale sign says it will feel very different - the rear lamps. The slight curve of the new lenses reveals that this car has one important new feature - Porsche's seven-speed double-clutch transmission.

Called PDK, this brilliant gearbox replaces the previous five-speed Tiptronic S conventional automatic transmission. With two clutches, the PDK set-up not only changes gears more swiftly, but also more smoothly, with virtually no interruption of torque.

Mated to the new gearbox is a new horizontally-opposed six-cylinder engine. The 3.8-litre boxer unit has twin turbos with their familiar variable turbine geometry, where the turbocharger blades automatically adjust to the amount of exhaust gas flow.

As a result, there is an incredible 650 Nm of torque from just under 2,000 rpm. If the Sport Plus button on the centre console is depressed, the Overboost feature increases charge pressure for up to 10 seconds to provide even more torque - 50 Nm extra - to hit a maximum of 700 Nm.

But the best thing about it is how lag-free and linear the Turbo feels and how all that power is delivered so smoothly to make this relatively small flat-six engine with forced induction feel like a bigger, naturally aspirated engine.

On the road, the performance of this all-wheel-drive 911 is nothing short of explosive. Floor the gas pedal and the Turbo takes off like Flight 911. The PDK double-clutch box also heralds the arrival of a new steering wheel option, with two long steering-mounted paddles with which to shift manually.

Extensive research and testing by Porsche engineers have endowed these two long, slim paddles with the perfect position, weight and feedback. They are a joy to pull, especially at high speed when the last thing you need to be distracted by is a fiddly piece of switchgear.

Of course, the new Turbo comes with other interesting toys too, such as the optional Porsche Torque Vectoring system - where the combination of a mechanical differential and electronic intervention heightens driving dynamics - and dynamically controlled engine mounts - where the engine mounts become softer or harder to suit the driving conditions.

So, in what seems like a contradiction, the 911 Turbo is more refined today even as its performance has made it a more explosive drive.

But far from making it appear Jekyll and Hyde-like, what Porsche has done is offer two distinct levels of driver enjoyment - it can be driven slowly and sweetly in the city, or it can charge down a twisty country road at full pelt.

And that is what makes this 911 Turbo so exciting.

Porsche 911 Turbo

Engine: 3,800cc flat-6 turbocharged
Transmission: 7-speed double-clutch
Max power: 500 hp @ 6,000 rpm
Max torque: 650 Nm @ 1,950-5,000 rpm (700 Nm @ 2,100-4,000 rpm with Overboost)
0-100 kmh: 3.6 secs (3.4 secs with Sport Chrono Package)
0-200 kmh: 11.6 secs
Top speed: 312 kmh
Price: from $638,888 (with COE)
Distributor: Stuttgart Auto
Tel: 6363-0911

This article was first published in The Business Times.