Price and equipmentBLUEBLOODS in the car industry are a rare thing.

In the premium mid-size sports sedan segment it’s generally accepted that the BMW 3 Series is the real deal. For nearly 40 years and through six generations, the Bavarian has been the one to beat.

Conversely, at the very opposite end of the scale, is the latest pretender – Infiniti’s Q50. Made by Nissan, it seems like the very embodiment of the showy upstart.

Except nothing could be further from the truth, because the Japanese rear-drive sports sedan boasts the oldest heritage of any on the entire planet.

By the time the first 3 Series came along in 1975 the Infiniti’s ancestor – the hallowed Skyline – had already come of age, beating even the iconic BMW 1602/2002 of the mid sixties by a decade.

Indeed, since 1957, it’s had nearly as many different identities as model changes, beginning as a Prince, before turning into Datsun, then Nissan, and then Infiniti.

Whether you know it as Skyline, 240K or G37, the Q50 is all there in the bloodline. In fact, the latter is sold as the Skyline by Infiniti in Japan.

The Q50 in question is the 3.5 Hybrid S Premium AWD, the $73,400 range topper, that is somewhere between about $10,000 and $30,000 cheaper than its Lexus IS350 and 3 Series Active Hybrid flagship equivalents.

Beyond the expected stuff like multi-zone climate control, leather trim and electric front seats, you’ll find dual touchscreen displays, GPS, digital radio, LED headlights with daytime running lights, Bluetooth audio and phone connectivity, paddle-shifters, a 14-speaker Bose stereo, Active Noise Control technology, keyless start, a sunroof and 19-inch wheels.

Furthermore, the driving experience is enhanced (or diluted, depending on your point of view) by a segment-first drive-by-wire Direct Adaptive Steering system, active lane control, radar-guided cruise control with low-speed autonomous braking, reverse camera with an around-view monitor, blind-spot warning, a back-up collision radar that brakes the car when backing out blindly, and active front lights with automatic high-beam.

All Q50s also come with a drive mode selector with four settings – Standard, Snow, Sport and Personal – allowing the driver to tweak steering weight and transmission responses.

At the entry level is a 2.2 GT powered by a Mercedes-sourced four-cylinder turbo-diesel as the Q50 opener, soon to be joined by four-pot petrol turbos.

InteriorHandsomely contemporary yet not much that’s memorable – like a David Jones catalogue model – that pretty much describes the styling inside and out.

Luckily then, the devil is in the Q50’s details.

Stepping inside the Premium, you’re immediately ensconced in a sumptuous interior. Lexus-esque instrument dials meet typical Japanese luxury sedan dashboard, so nothing really new here at first glance.

But explore the initially complicated multimedia screen and there’s a world of functionality at your fingertips. It does take some familiarisation, but once mastered, you’re likely to enjoy the astounding amount of control and customisation.

Among the many features are apps with software update capability, finger-flick zoom/scroll for the dual screens and a customisable presentation and layout.

The system can also learn driver’s preferences and settings, and includes full-sentence voice commands.

What’s missing? About the only obvious thing is a digital auxiliary speedo, either as part of a head-up display or within the analogue dials.

Everything else is present – from a spacious and roomy front-seat environment to a well-ventilated and very useable driving position. Extra marks go to the surround-view reverse camera, handy voice recognition system, straightforward Bluetooth set-up and easy sat-nav interface.

The front cushions and backrests are particularly comfortable over longer journeys, providing support where needed yet sufficient softness when all you want to do is sink into the supple leather. Infiniti reckons it used NASA technology to help out here.

Rear-seat legroom is OK if you’re under 180cm, though the standard sunroof robs some headspace, and there could be a bit more storage otherwise the second row is as inviting as snug as the front seat area.

But the 400-litre boot is tiny due to the hybrid gubbins, barring any cabin access that might boost practicality. It’s a shame because the dearth of luggage space compromises what is otherwise a practical family car alternative.

For that in the Q50 you’ll have to settle for one of the variety of cheaper four-cylinder models.

Engine and transmissionWith a 268kW/546Nm 3.5-litre V6 petrol/electric combination driving all four wheels via a seven-speed DCT dual-clutch transmission, you’d expect the Q50 to be a formidable sports sedan.

And in a way, it is, though a fast grand tourer is probably a more accurate description.

As previously mentioned, there are four driving modes – Eco, Normal, Sport and Personal, with the latter allowing for configurable steering and throttle response settings according to the driver’s preferences.

In Normal, the performance (even on 98 RON premium unleaded as tested) is strong but unremarkable at first, until you learn to flex your foot more than you might be used to, to overcome the pedal travel.

Then you discover Sport and the Infiniti starts to live up to the drivetrain potential, leaping off the line (to the point of having the rear wheels wiggle its tail a little in the wet despite the AWD), and then just pulling heartily as the needle rises up the rev range.

Some caution is recommended the 3.5 V6 Hybrid is a refined mechanical proposition, and so speeding excessively can be a very real danger. Noise from both the road and from the car itself is subdued – though there’s that almighty VQ35 roar in the background if you listen carefully enough.

Speaking of sounds, in manual paddleshift mode, Nissan’s gimmicky Downshift Rev Matching algorithm ups the sports sedan ante with some perfect-every-time double-declutching action as the DCT shuffles down through its lower ratios – 370Z-style.

The Q50 flagship’s rapidness is matched by some remarkable fuel consumption figures. We averaged 8.9L/100km over a range of performance driving scenarios, which included urban and rural courses. That’s not too far off the official 7.2L/100km average.

Note that this Q50 can amble along up to 100km/h in full electric mode for short periods, courtesy of a lithium-ion battery pack tucked in the rear of the vehicle.

Ride and handlingMuch has been made about the virtues or otherwise of the Q50’s drive-by-wire steering system.

Dubbed Direct Adaptive Steering, it’s a steer-by-wire system that replaces the steering rack with three ECU modules (with triple fail-safe measures as part of 400,000km of real-world testing) to eliminate kickback, the company claims.

The truth is, if you weren’t aware, you’d probably just think of it as a sharp and taut handler, with excellent body control, superb all-weather grip afforded by the AWD hardware underneath, and rather remote steering feel.

Except for a dearth of road surface feedback – something you quickly get used to anyway – this Q50 corners with poise and agility, full stop. There’s a definite linearity to the way the Infiniti tips into turns.

At normal to high speeds, anyway around town, in a tight U-turn or during lock-to-lock parking manoeuvres, the steering changes at the extremes, from sharp effortlessness to a sudden, clumpy jolt that feels weird and can result in a complete loss of electric assistance for a moment or two.

As we said, we could only prompt such odd responses in extreme lock-to-lock situations, because otherwise the Infiniti’s helm is a smooth model of faithful (if remote) reaction.

We went for a wet-weather country road blast one night, and marvelled at how secure and controlled the whole car felt, revealing its dynamic heritage while racing through tight turns and wide corners alike.

In such conditions, there’s an on-rails surety to the Q50’s roadholding that makes you feel glad you’re ensconced within its isolated cabin.

Furthermore, the 19-inch wheel and tyre package does not induce a hard ride, which is an unexpected treat, while road noise is also well contained.

Again, the Skyline’s 57-year experience seems to show.

Safety and servicing A five-star ANCAP crash-test rating has been achieved by all rear-wheel drive Q50 variants. None exists for the AWD model under review here, but expect a similar outcome.

Infiniti also offers fixed-price scheduled servicing covering the first four years of ownership or 80,000km.

Verdict When the worst thing you can say about a new BMW 3 Series rival relates to its fussy nose and 2006 Hyundai Elantra rear-end treatments, then someone must be doing something right.

Yes, the Q50 3.5 Hybrid S Premium AWD’s drive-by-wire steering can get a bit gloopy and lumpy if you pile on the lock-to-lock, but in normal driving conditions it feels fast, agile and reactive (if a tad too remote, feedback wise).

What we have here is a Japanese sports sedan with the longest premium sports sedan heritage on Earth.

The V37 generation leverages that to be a rapid and invigorating grand touring sedan with excellent all-weather security combined with impressive fuel economy potential.

But the boot is disappointingly small because of the electric motor/battery gubbins packed within, limiting this car’s practicality. If you need luggage capacity then maybe try one of the other non-Hybrid variants instead.

Yet even as it stands, the flagship Q50 has personality, performance, poise and purpose. There’s more than a bit of Skyline underneath that pretentious Infiniti mask, and that’s no bad thing in our book.

Rivals1. Lexus IS 300h F Sport, from $68,700 plus on-roads
Sharp, sporty and futuristic in presentation, the rear-drive four-pot electric hybrid 300h is the pick of the third-gen IS range, offering refined performance and economy in a reasonably priced package.

2. BMW ActiveHybrid 3, from $100,200 plus on-roads
Handsomely designed, well specified and a real technological powerhouse in terms of efficiency as well as performance, the Bavarian hybrid sets a driveability benchmark… but at a hefty price.

3. Lexus ES 300h Sports Luxury, from $72,000 plus on-roads
In the showroom Lexus’ midsized luxury sedan dazzles with heaps of space, high-tech features and classy styling, but turgid dynamics and disappointing refinement levels betray the ES’ Camry origins.

SpecsMake and model: Infiniti Q50 Hybrid S Premium AWD
Engine type: 3.5-litre V6 petrol/electric motor/lithium-ion battery
Layout: AWD
Power: 268kW (in total, including 50kW motor)
Torque: 546Nm (in total including 50kW motor)
Transmission: 7-speed dual clutch
0-100km: 5.4s
Fuel consumption: 7.2L/100km
CO2 rating: 169g/km
Dimensions: L/W/H/WB 4800/1820/1455/2800mm
Weight: 1853kg (tare mass)
Suspension f/r: Double wishbone/multi-link
Steering: electric rack and pinion
Price: From $73,400