Infiniti raised eyebrows with its recent decision to toss out tradition and adopt an entirely new naming convention for its fleet. The move coincides with the company making a design and engineering push to have its offerings ranked alongside the high-performance luxury Audi-BMW-Benz triumvirate. The first model to get a makeover and new nomenclature for 2014 is the Q50, the long-awaited replacement for the G37 Sedan. And if the results – including some particularly jaw-dropping feats of futuristic tech – are a taste of what's to come for the rest of the company's line, then Infiniti is poised to take on the world.

At first glance, the Q50 looks similar to its predecessor, mainly because it rides on the same 112.2-inch wheelbase and shares a lot of the same stylish bits and pieces. But a closer look reveals it's actually slightly lower, longer, and wider, and, consequently, has a more menacing stance. It also has a larger "double arch" front grille, LED headlights, and daytime running lights.

Inside, the changes are far less subtle. To the contrary, Infiniti has completely redesigned and upgraded everything both in materials and presentation. This is a much more refined car. A new dual-cowl dashboard features a redesigned center stack dominated by a pair of touchscreens (8-inches and 7-inches). The two allow control of the car's entire HVAC and infotainment systems, as well as other vehicle settings, including drive mode (Standard, Sport, Eco, and Snow), shift patterns, and even throttle sensitivity. Using the touchscreens was completely intuitive and we like that they're customizable.

Two powertrain options are available: An updated version of Nissan/Infiniti's widely used 3.7-liter V6; and a Direct Response Hybrid, which combines a 3.5-liter 24-valve DOHC aluminum-alloy V6 (and compact laminated lithium-ion battery design) with an innovative one-motor/two-clutch motor control. The hybrid's V6 is rated at 302 horsepower and 258 lb-ft of torque, while the advanced 50 kW electric motor is rated at 67 horsepower and 214 lb-ft of torque. Net power for the hybrid is 360 horsepower, and in our tests provided strong acceleration with lean fuel economy: We were able to get around 31 mpg in mixed highway/city driving. The gas-powered model didn't fare as well at the pump – guzzling in the low 20s mpg. Whichever your preference, both engines are powerful and deliver the goods every time you punch the accelerator. There's no question the Q50 is a far more refined, better equipped and better performing vehicle than its predecessor.

While all of the above accolades are important, they pale in comparison to the Q50's ability to – quite literally – drive itself.

For an extra five grand, the Q50 can be outfitted with Direct Adaptive Steering, Active Lane Control, Blind-Spot Monitoring, Adaptive Cruise Control, and Predictive Forward Collision Warning, among other safety tech bells and whistles. Together they are the most comprehensive electronic driver aid packages we've come across.

While other vehicles feature similar lane departure systems (most notably the new Mercedes-Benz S-Class), the Q50 is unique in that it uses Direct Adaptive Steering, Infiniti's version of a drive-by-wire electrical steering system, to initiate course corrections instead of dragging a brake. And when all the systems are engaged, the car is capable of automatically keeping itself a safe distance from the vehicle in front, stay centered in a lane, and even navigate around sweeping curves, without any input from the driver. We were able to drive safely for 35 miles without using hands or feet – didn't touch the steering wheel, depress the accelerator, or tap the breaks, even once.

It's still not foolproof, however. For instance, it can only navigate around a certain radius of turn (which isn't consistent) before the system requests that the driver grab the steering wheel and take control. We also thought the vehicle hugged the lane markers a little too closely or too long for our comfort before maneuvering back to the center of the lane. We tried it on the busy streets of Boston and in some quaint New Hampshire and Maine suburbs. More often than not, we wound up in oncoming traffic, or hurdling toward a ditch, gulley, or guardrail rather than driving straight down the thoroughfare. For this reason, the system is only suitable for highway driving, and not precise or reliable enough for crowded city or suburban driving. Still, the Q50 is the best sports sedan that Infiniti has ever built and fully capable of competing with the top players – the Audi A4, BMW 3-Series, and Lexus IS – in the market. [Available late summer. From $37,605, as tested $53,000; infinitiusa.com