We like
Strong performance, sharp and fluent steering, solid handling, comfortable seats, equipment for the money

Room for improvement
Tough ride quality, hefty kerb weight, poor stability control tune, dated and unintuitive infotainment

Price and equipment

A $69,900 (plus on-road costs) pricetag for the Infiniti Q50 3.0t Sport Premium mirrors that of medium sedan rivals, the Audi A4 2.0 TFSI Sport and BMW 330i.

That German duo get 185kW 2.0-litre turbo engines, versus the 224kW 3.0-litre twin-turbo V6 here, while buyers will need to pay around $7500 in options when they are specified to Infiniti standards.

A sunroof is standard on the Infiniti, for example, but it adds $1950 to the Audi and $2245 to the BMW. Adaptive cruise is included with this Q50 but adds $1880 to the 3 Series (although bundled with automatic park assistance unavailable here).

Meanwhile premium audio and heated seats feature with this Sport Premium but together add $1100 to the 2.0 TFSI Sport and $2912 to the 330i (the latter packaged with an electric rear sunblind).

Interior

First impressions are solid inside the Q50 3.0t Sport Premium. The front seats are plushly padded and wrapped in high-quality leather, the small steering wheel is electrically adjustable and falls neatly to hand, and the soft-touch door trims and leather-trimmed kneepads are lush.

There are some issues, however, and they particularly grate given the pricetag.

By far the biggest of these is Infiniti’s twin-screen infotainment system. In a visual sense the low-resolution top screen looks different – and includes a different font – to the bottom control screen. However, the way each screen duplicates some functions, buries others inside sub-menus and misses some entirely is most frustrating.

For example, the music track-change function takes the form of a physical button on the lower dashboard. It is not possible to change tracks from the steering wheel that only controls entering sub-menus, and nor does the superfluous centre console control rotary dial do anything but duplicate (triplicate?) what both the steering wheel buttons and touchscreens can activate.

Yet the Infiniti lacks basics such as a digital speedometer, while a head-up display is not available.

While competitors have moved to ‘one shot’ voice control systems to ‘speak in’ an entire street address for the sat-nav system, the Q50’s voice control is also reserved for phone and audio only.

The missing technology is at least offset by kit rivals charge extra for, such as the great 14-speaker Bose audio system and heated seats that even boast electric side-bolster adjustment.

Space up front is decent, but storage space is limited to two console cupholders, with nowhere to store a smartphone other than in the small console box. Rear passengers only get a fold-down armrest housing two cupholders, with back door pockets also lacking, and the standard sunroof severely restricts headroom in the back where legroom is also among the tightest in the segment.

The bench is decently comfortable, however, while air-vents are provided and the boot is class leading with a 500-litre cavity.

Engine and transmission

Infiniti curiously does not provide a 0-100km/h claim for Q50’s twin-turbo V6, but the hybrid V6 with 268kW/546Nm will sprint to triple-figure speed in 5.1 seconds. Expect this 224kW/400Nm model to poll in the 5.8sec region, which feels about right.

That acceleration would be identical to that of the A4 2.0 TFSI Sport and 330i, the latter of which is the lightest car in the segment at 1495kg. The Q50 3.0t Sport Premium, by contrast, weighs a hefty 1784kg.

Higher outputs simply offset the weight burden, although the V6 is a sweet engine and its torque rush feels stronger and more sustained than any turbo four-cylinder rival.

At least the seven-speed automatic is fluent and the Sport mode is intelligent enough to detect when the driver is cruising or steering more enthusiastically.

The auto never becomes quite snappy enough when really pressing on, though, even when using the paddleshifters in manual mode.

Ride and handling

Infiniti’s second-generation direct adaptive steering (DAS) is as improved as the newly introduced dynamic digital suspension (DDS) that replaces the previous fixed-rate sports suspension.

DAS is a world-first fully electric steering system that does away with any mechanical linkage with the front wheels, but the original iteration was flawed.

The updated version still has seven modes – Comfort, Sport, Sport+, with separate selections of each for response or weight – but Infiniti now only needs to retain the extremes: Comfort is fluent around town, Sport+ pin-sharp on a country road.

There is no real road feel, but that is only one aspect of steering quality, and DAS now gets decent ticks for consistency and accuracy.

The chassis’ DDS system, likewise, provides controlled if not supple ride quality. In Normal mode the suspension is too jiggly and abrupt around town, but it improves at speed and at least for a sports-focused model it keeps the body level.

Unfortunately, there is only one electronic stability control (ESC) mode that is too abrupt and harsh. When overtaking on the wrong side of a country road, the system twice cut power for at least a second for no apparent reason. The Q50 is left feeling enthusiastic, but dynamically confused.

The extra mass fails to help make this Infiniti any quieter on coarse-chip surfaces, either. Rivals offering 19-inch tyres are similarly noisy on coarse-chip roads.

Safety and servicing

The Q50 3.0t Sport Premium features seven airbags (including dual front, front-side, full-length curtain and driver’s knee protection), ABS and switchable electronic stability control (ESC), blind-spot assistance, lane-departure warning and lane-keep assistance, forward collision warning with autonomous emergency braking (AEB), front and rear parking sensors and a surround-view camera.

Euro NCAP tested the Infiniti Q50 in 2011 and it scored five stars with 35.76 out of 37 points.

Infiniti’s capped-price servicing program includes annual or 15,000km intervals, at an average cost of $449 for each of the first four check-ups.

Verdict

Infiniti has hugely improved the Q50 within just two years. DAS is now decent and DDS mostly mends the issues with the former suspension. The twin-turbo V6 offers strong performance, too.

Ultimately, though, the Sport Premium still feels more like a $60K sedan than a $70K one. Adding extra equipment and power is not quite enough to best far more sophisticated German rivals, because ultimately this Infiniti continues to be a rough diamond that lacks polish.

Particularly given the Q50’s unpretentious Nissan Skyline lineage, there is absolutely no shame in differentiating this Japanese medium sedan from the competition by pricing it somewhere between, say, a sub-$50K Holden Calais V and a $70K-plus BMW 330i.

Infiniti is unlikely to lower pricing and budge from its determination to succeed against the segment stalwarts, however – which means the Q50 will need to continue its speedy rate of improvement in order to become decently competitive among fierce rivals.

Rivals

Audi A4 2.0 TFSI quattro from $69,900 plus on-road costs
Superb cabin and performance, dynamics second to 330i.

BMW 330i from $69,900 plus on-road costs
The driver’s choice with benchmark engine and handling.