LEXUS is fighting the super sports sedan competition with its own tools and on its own terms. The GS F is the F division’s fourth product following the discontinued IS F compact sedan and LF A supercar, and the current RC F compact coupe.

Priced from $148,800 plus on-road costs, the GS F large sedan is more focused than a $20,000-dearer Audi S6 but is less explosive than the $35,000-pricier BMW M5 Pure Edition. Each executive express from Germany boasts a turbocharged V8 engine.

Lexus is bringing a different gun to the fight in the form of a 5.0-litre naturally aspirated V8 producing 530Nm of torque between 4800rpm until 5600rpm, and 351kW of power at 7100rpm, just below a 7300rpm redline.

Its specifications read exactly like today’s Ford Mustang – capacity and peak torque are identical. Consider that this F model is based on the rear-wheel-drive GS released in 2012, but with German Sachs fixed dampers, French Michelin Pilot Sport tyres and Italian Brembo brakes, and the new Japanese sedan reads like a multicultural parts-bin special.

Lexus has proven it can bring quality, technology and equipment to the table, though, and in this regard the GS F doesn’t disappoint. It is immaculately finished and indulgently specified, with a sunroof, heated front and rear leather/Alcantara seats, 12.3-inch colour screen and adaptive driver aids all standard.

Ignoring the availability of orange exterior paint – although it’s impossible to miss the orange brake calipers standard with every colour – and the carbon-fibre lip spoiler, and the GS F still looks like a touring car.

Based on a four-year-old design, albeit a facelifted version, the GS F doesn’t feel as special as newer $150,000 vehicles. The addition of fake rivets atop the Alcantara-clad dashboard and aluminium or carbon trim struggles to elevate the dated plastics.

The sizeable screen also mates with an unintuitive Lexus mouse-controller that adjusts a cursor to access functions. A digital radio, satellite navigation, concierge services and 17-speaker Mark Levinson stereo are standard, however.

The GS F is not as roomy as an M5 and the chunky front seats restrict rear legroom as much as the sunroof reduces headroom. The restrictive centre tunnel relegates the GS F to a comfortable four- rather than five-seater.

The seats front and rear are superb and a low driving position and small three-spoke steering wheel are a perfect place to settle in and start up a V8 engine of exquisite beauty.

Incisive throttle response immediately feels far more natural than the all-or-nothing response of an M5, and the clean, metallic howl as the tachometer swings to its lofty heights is inspiring.

Claiming zero to 100km/h in 4.6 seconds is merely average for the price these days. Even an S6 is two-tenths faster. If anything the GS F can feel slower than its claim due to the lack of turbocharged boost.

Thankfully the eight-speed automatic is snappy when used in its manual mode – accessed via either the tipshifter or steering wheel paddles.

Left to its own devices, however, even the most aggressive Sport S+ mode instructs the transmission to drop revs too quickly to the detriment of response. It’s especially disappointing when the mode already places above Eco, Normal and Sport S.

There are other modes, too, including Standard, Track and Slalom designed to act on the Torque Vectoring Differential (TVD) that can juggle drive between each rear wheel. When Sport S+ is engaged, a VDIM Expert mode can also be employed as a stability control mode with severely reduced intervention.

As with the transmission setting, the stability control calibration in Sport S+ is not sporty enough, restricting even minute amounts of rear movement and limiting throttle adjustability. The work of the TVD can never be fully realised unless VDIM Expert is employed – but as even the Mustang proves, a standard stability control mode can be less restrictive without being lax.

Otherwise this Lexus is dynamically superb. The brand says it benchmarked its RC F stable-mate for handling character, yet despite the GS F being demonstrably larger – adding two back doors, genuine rear legroom and a large 520-litre boot – this sedan is only 45kg heavier, at 1825kg.

The stick from the tyres is astounding, but the GS F is not all grip ahead of balance. The dampers keep the front feeling tight when turning into a corner before progressively shifting weight to the rear without lurching wildly. The agility for such a large sedan is first rate.

Moving from road to circuit at the GS F national media launch held around the Adelaide Hills then Mallala raceway, this Lexus didn’t wilt. In fact it only helped enliven the otherwise light and accurate steering and reinforced the supreme stopping ability of the 380mm front/345mm rear slotted disc brakes.

It also highlighted that the GS F is perhaps more impressive during maximum attack driving than in typical urban and country touring conditions. The downside to the fixed dampers is ride quality that is too hard for an executive sedan, much less one that costs $150,000. This Lexus always feels busy and lumpy over any surface.

German competitors and even the HSV GTS utilise multi-mode adaptive suspension that are also multi-talented in balancing comfort with sportiness. This is one area where Lexus goes its own way not for the better.

With a smoother ride, it would be easier to overlook the detail flaws of the GS F. It otherwise has all the gear, both in equipment, drivetrain and chassis terms, to carve a unique place among the super sports sedan fraternity.

With a little extra polish, it could best utilise its unique weaponry to upset both cheaper and more expensive models.