Introduction

The Infiniti Q50 is a sports sedan with striking sheetmetal and road manners bordering on brilliant. 

The 2017 Infiniti Q50 lineup spans 14 models. Powertrains include a turbocharged four-cylinder, a turbocharged V6 in two states of tune, and a hybrid gas-electric. All are available with all-wheel drive or rear-wheel drive. 

New for 2017 is the Infiniti Q50 Sport model with the four-cylinder engine. Also new for 2017 is a Design package for V6 models, and some minor upgrades to equipment. The Q50 was last redesigned for 2014. 

The Infiniti Q50 competes in a class of heavy hitters, including the Cadillac ATS and Audi A4. It's bigger than rivals like the BMW 3 Series and Mercedes-Benz C-Class, but smaller than the BMW 5 Series or Jaguar XF. 

The Q50 base engine is a 2.0-liter turbocharged four-cylinder making 208 horsepower and 258 pound-feet of torque. The available twin-turbocharged 3.0-liter V6 makes 300 hp and 295 lb-ft, while another twin-turbo V6 is called the Red Sport 400 because it makes 400 horsepower, with 350 lb-ft of torque; it's a delight that can shoot the Q50 from zero to sixty in 4.5 seconds. All engines use a 7-speed automatic transmission with a manual mode and available shifting paddles. 

Fuel economy is highest for the Hybrid model, with an EPA-rated 28/34/30 mpg City/Highway/Combined. A Red Sport with all-wheel drive rates just 19/26/22 mpg. 

Lineup

The 2017 Infiniti Q50 ($33,950) comes standard with leatherette upholstery, dual-zone climate control with micron air filter. 

The Sport and Red Sport feature Digital Dynamic Suspension, bigger brakes, 19-inch wheels, leather sport seats, aluminum pedals and magnesium shift paddles. Safety features include surround-view cameras, adaptive cruise control, blind-spot monitors, and forward-collision warning systems with automatic emergency braking. 

Walkaround

The Q50 is bigger than its rivals, but looks smaller when you stand back. It carries some of the flowing sensuality of the bigger Infiniti Q70 sedan, in its exaggerated curves behind the rear doors that were designed to suggest waves in the sea. The sleek organic shape is reflected by a low 0.26 coefficient of drag, apparently unhindered by the creases in the sheetmetal, especially the two fender lines that meet near the A pillars. 

The boomerang brackets in the double-arch grille are like those in the Lexus IS, but their hourglass shape is more in tune with the Q50's silhouette. The LED lighting is both smooth and aggressive. 

Interior

A sweeping asymmetric arc runs down the console, keeping the controls focused on the driver and the cabin feeling like a cockpit. However the other side of the arc is dominated by Infiniti's haphazard InTouch, two touchscreens with redundant hard keys. InTouch replaces most vehicle and infotainment controls with menus on the capacitive-touch displays. The larger touchscreen on top of the dash displays the more common functions, while the smaller screen is used for infotainment and other things. 

The Q50's interior materials are as luxurious as those in a German sedan, and the cabin is as quiet. In fact the engine noise is almost too muted for a sports sedan. 

Great front seats follow those in the latest Nissan Altima, using cushion technology learned from NASA, the so-called zero-gravity design. It's literally space-age, but actually not so much; pinpoint body pressure is simply distributed more evenly, for comfort over long hours in the seat. The Sport model seats have extendable thigh bolsters for the driver. 

Rear passengers have more space than is average for the class, but legroom isn't great, and a six-footer might find his or her head rubbing the ceiling. 

The trunk is larger than average, at 18 cubic feet, although the Hybrid loses 3.9 cubic feet to the battery pack, and you can't get a split-folding rear seat with the Hybrid. 

Driving Impression

With 208 horsepower and 258 pound-feet of torque, the base 2.0-liter turbocharged engine doesn't lack for power. 

With the twin-turbocharged V6 engines, the difference between 300 horsepower and 400 hp is mostly in turbo boost, with 8.7 psi available in the regular V6 and 14.7 psi in the faster-spinning Red Sport V6, whose 350 pound-feet of torque (vs 295 lb-ft) is available all the way from 1600 to 5200 rpm. It redlines at an exciting 6400 rpm. 

We said the Q50 had brilliant road manners, but that only makes it a close match for its competitors. It stays fairly flat in corners, has quick response from either of its two steering systems, rides comfortably, and is stable at high speed. But when it's pushed though a curvy canyon, flaws appear. It doesn't want to take a set in a turn if it's at the limit of grip. It's not in the same league as the BWW M3. 

And under heavy braking, it shimmies. On the track, not even the bigger Sport brakes are up to the task, as they fade after too few laps. But the 7-speed automatic transmission provides nice throttle-blipped downshifts and remarkably little driveline shock. 

The Drive Mode Selector offers a bewildering capability of more than 300 settings to set response from the throttle, steering, transmission, stability control, and suspension. Maybe we just never found the right one. 

And the handling can be improved with options. There's the Dynamic Digital Suspension, with its electronically controlled valves in the dampers, to stiffen the ride in Sport or Sport+ modes. It's not too firm on the street in those modes, and they reduce body roll, but they also make the car jiggle a bit in the corners. 

There's also the steer-by-wire Direct Adaptive Steering, with seven settings within the Standard and Sport+ modes, for resistance and responsiveness. In Standard mode it feels much like any electric-assist power steering system; it erases some bumps that can jerk the steering wheel, along with some of the feel that makes cornering fun. 

In the Sport+ mode, it does what you want it to, but maybe too much. It gets quicker at low speeds, and heavier and slower at higher speeds, for stability. The ratio varies a remarkable amount, between 12:1 and more than 20:1; it's almost too quick at low speeds, while being darty and too weighty at speed. You might be happier in Standard or Sport mode, while avoiding Sport+. If not avoiding Direct Adaptive Steering altogether. 

The base steering in the Red Sport has a 15:1 ratio. It's noticeably lighter and more natural feeling than the optional DAS. 

We haven't had the chance to drive the 300-horsepower V6, only the terrific 400-horsepower version (that's 25 hp less than the BMW M3), which is reason alone to buy the Red Sport. It delivers willing power (as it should) and lets out a muffled howl when hammered. 

Too bad the Red Sport 400 doesn't have track-ready hardware, and its Dunlop run-flat summer tires that don't provide a lot of grip (245/40R19 front, 265/32R19 rear). Even on the road, it's easy to break the rear tires loose, although stability control saves you. 

The Hybrid is also quick, with 360 horsepower from a special version of Infiniti's 3.5-liter V6 and a 50-kw motor. Its unique dual-clutch hybrid system uses a dry clutch in front of the transmission and motor, with a wet clutch behind it. This smoothes the transmission of power from one source to the other, and allows the car to gently take off on electric power alone; it also shuts off the engine so it glides more. 

The throttle response is well coordinated to the clutches, but the braking doesn't quite measure up, as it gets a bit murky under the pedal, just before the car comes to a complete slow stop. 

Summary

Seven distinct models, seven decision to make. We'll make it easy, and say stick to the base 2.0t with rear-wheel drive. It's the cheapest, simplest, and has all the virtues, including looks and powertrain. No one will know you don't have 400 horsepower under the hood, and even if you did, it wouldn't match the BMW M3. 

Sam Moses contributed to this report.