Silence is golden. Seen but not heard. The quiet achiever. Any of these old adages could have been written for Japanese luxury brand Lexus.

For a company so intent on making a big noise in the premium car segment, they certainly go about their business in a very quiet way. And no model illustrates that philosophy more clearly than their flagship LS600h – a whisper-quiet, hybrid-powered luxury limousine that pretty much sums up what Lexus is all about.

Quiet, unobtrusive but ever more formidable. Lexus’ marketing campaign even urges potential LS buyers to “announce yourself without saying a word”.

Now, though, it seems the Japanese marque’s stealth attack on the big German brands is taking a new direction. Having spent decades sneaking up from behind, Lexus is getting ready to pull out and overtake. A new F Sport edition of the LS600h has put this ultra-refined machine into the fast lane – answering the perennial question about whether Lexus could make cars as fun to drive as they are to ride in.

This one’s a hoot – well, a well-manned hoot, anyway. Combining a muscular V8 engine with the added thrust of an electric hybrid motor, the LS600h enjoys a thumping output of 327 kilowatts – taking a very quick, very comfortable and very quiet 5.7 seconds of rather extraordinary acceleration to get you to the speed limit.

The F Sport was unveiled late in 2012 – about six months after the relaunch of the latest LS range. It costs $217,900 – a $25,000 premium over the “basic” LS460 entry-level model – but that’s quite a bargain when you consider the amount of additional kit it entails. It’s the first Lexus sedan to enjoy all-wheel-drive grip – part of a comprehensively upgraded handling package that turns this always refined, luxurious machine into a seriously fun thing to drive.

The package includes sports-tuned air suspension, adjustable to deliver surprisingly agile and focused handling; upgraded Brembo brakes and a five-mode Drive Mode that controls a variety of engine, transmission and chassis settings.

It’s the first Lexus to use the company’s new active stabiliser bar technology – which Lexus says further adds to its body control and steering response characteristics. They also boast that improved body bonding techniques have delivered a 60 per cent increase in body rigidity across the LS range.

Ride height has been lowered by 10mm to ensure a more athletic, sporty gait. Big 19-inch alloys, F Sport badging and mesh grille treatment, aggressive spoiler and body skirts and unique fog lights sharpen its appearance. So it’s a worthy flagship of the LS model range – which starts with the V8-powered LS460, hybrid LS600h and, at the most exclusive end of the spectrum, a long-wheelbase version of the LS600h.

Even in standard guise, though, the LS boasts quite a bag of tricks. My favourite was the “Climate Concierge” function – which Lexus claims is one of three world firsts on the model. In a nutshell, it uses 13 internal sensors to recognise when temperatures are particularly cold or hot and adjusts the cabin’s functions accordingly. On a particularly cold morning, I got into the Lexus and found, to my delight, that the steering wheel heater (yes, it has one of those) and the seat heaters had been automatically activated for my comfort.

The seats also have internal cooling, are adjustable in 16 directions and some models even feature a passenger-seat “ottoman” which, Lexus says, improves comfort by “reducing heel pressure by 45 per cent and thigh pressure by 10 per cent”. How do they measure this stuff? I can confirm, however, that the seats are particularly comfy – ours were trimmed in the just-released colour of Champagne White – not recommended for small kids with ice creams.

Electronic aids for the driver include a driver alert monitor and pre-collision safety system; blind spot monitor with lane-changing function and automatic high-beam for the superb LED headlamps.

In the cabin, that legendary Lexus attention to detail remains. The air conditioning system, for instance, releases minute “Nano” particles of negatively-charged ions, wrapped in water molecules, into the cabin to neutralise airborne particles and odours. Lexus claims that the system even helps moisturise your skin and hair.

Design-wise, too, the latest LS cabin has lifted this model onto a par with its German competitors. I’ve always felt that, as plush as they were, the interiors of these flagship Lexus models were a bit like those McMansions you see in the real estate section – designed by someone with lots of money but not much taste. That’s quite the opposite these days – the sweeping lines, the judicious use of luxury materials and high-end finishes – produce a cabin ambience that more than justifies the LS600’s price tag.

The interior wood finish uses a traditional Japanese method called Shimamoku – which involves painstaking layering of different coloured timbers – a process taking 67 steps over 38 days.

There’s the massive 12.3-inch centre screen – probably bigger than any other vehicle on the market – which displays with vivid clarity the Lexus Remote Touch system which allows you to toggle between about 10 different categories of cabin and vehicle functions.

The satellite navigation display is superb, and the GPS system is linked to the car’s clock that is automatically updated when you drive from one time zone to another. The trip computer shows not only your current fuel consumption but also the personal best of the vehicle, and the date it was set.

The 450-watt, 19-speaker Mark Levinson sound system is sublime – thanks apparently to 2000 hours spent tuning it, while there’s also a Blu-Ray rear-seat entertainment system.

I took a turn in the back seat of the Lexus as well – handing over the steering duties to a family member for a while – and that’s certainly no hardship – even if the F Sport is particularly fun to steer. Some models even offer two rear, adjustable bucket seats instead of the traditional three.

Which brings me to one last point about the LS. Lexus measured the Articulation Index in the rear seats and is delighted to say that it scored almost 100 when the car is travelling at 100km/h. Articulation Index, you might ask? It’s a Lexus term – to measure the car’s quietness.

LEXUS LS600h F-SPORT

DETAILS: Four-door, four or five-seat full-sized luxury sedan with V8 hybrid engine and eight-speed automatic transmission.

TECH STUFF: 5-litre V8 engine (290kW) combined with electric motor to produce 327kW, 520Nm, CVT transmission with eight-speed step-shift function; all-wheel-drive.

FEATURES: 10 airbags, pre-crash seatbelts, vehicle stability control and dynamic integrated management, driver fatigue alert, ABS with brakeforce distribution, tradition control, adaptive variable suspension, blind spot monitors, frontal collision avoidance system; advanced climate control system with “Climate Concierce” function; premium audio system, electric seats, windows and mirrors, automatic headlights and wipers with auto high-beam function; 12.5-inch display screen with satellite navigation, hard-drive storage; Bluetooth connectivity.

THIRST: 8.6L/100km combined figure.

PERFORMANCE: 0-100km/h in 5.7 seconds.

VERDICT: Like an Earth-bound Lear Jet. Only quieter.

Prices quoted do not include statutory and dealer on-road charges unless otherwise stated. Prices correct at time of writing.