The Infiniti Q50 competes with some accomplished sport sedans, like the BMW 3-Series, Cadillac ATS, Audi A4, and Mercedes-Benz C-Class.
On the road, it is a fairly close match for those cars. The car stays fairly flat in corners, has quick response from either of its two steering systems, and rides fairly comfortably.
Push the Q50 on a canyon road or a racetrack, however, and its flaws become apparent. When nearing the limits of grip, it doesn't really want to take a set in a turn, though it is stable at higher speeds. Under heavy braking, however, that stability goes out the window and the car shimmies as it slows. Infiniti's brakes, even the larger sport brakes, also aren't up to the rigors of track duty, fading too quickly. Still, we give the Q50 a 7 in our new ratings system, adding a point for generally agile handling and willing power from any engine. (Read more about how we rate cars.)
The Red Sport 400 sounds like a BMW M3 competitor and it's just 25 horsepower shy of that car. However, like other Q50's, it doesn't have track-ready hardware, despite the fact that it comes with big tires, 245/40R19s up front and 265/32R19s out back. They are Dunlap SP Sport Maxx 050 summer run-flat tires that don't provide a lot of grip. With all that power on tap, it is easy to break the rear tires loose in situations like punching it for passing or adding a bit of throttle in a turn. A grippier tire would aid this car's traction and handling.
Buyers can add some features meant to improve the handling. Infiniti offers a Dynamic Digital Suspension that has its pluses and minuses. It uses dampers with electronically controlled valves that provide a stiffer ride in Sport or Sport+ modes. The ride is firm but livable in the Standard mode—as it should be in a sport sedan—and the Sport modes make it a bit jiggly while helping to reduce body roll through corners.
Speaking of modes, the Q50's Drive Mode Selector offers a ridiculous total of more than 300 personalized settings that alter the engine, transmission, electric power steering, optional Direct Adaptive Steering and Dynamic Digital Suspension, and the electronic stability control. Our advice is to try the various settings, personalize them down to one that you like, and just use it.
Infiniti's "steer-by-wire" Direct Adaptive Steering (DAS) is also worthy of note. Infiniti boasts that it can respond faster than a mechanical system because there are no mechanical linkages, and it is very customizable. In fact, it is available in seven settings.
Even within the Standard and Sport+ modes, the DAS can be adjusted for weight and responsiveness. In the Standard mode it feels much like any other electric-assist power steering system. While it filters out some bumps that can jerk the steering wheel, it also lacks some of the feel that can make steering satisfying.
In the Sport+ mode DAS does many of the things you'd want from a steering system. It becomes heavy and slower (read: stable) at highway speeds, wants to return to center, and gets quicker at low speeds. In fact, the ratio varies between 12:1 and more than 20:1. It is also almost too quick at low speeds, and darty and too weighty on the highway. Some of these issues can be mitigated by simply choosing the Sport or Standard modes instead of Sport+.
The base steering is a rack-based electric-assist power steering system with a 15:1 ratio in the Red Sport. It is noticeably lighter than the steer-by-wire system but feels a bit more natural.
Power and more power
The engine lineup includes a 2.0-liter turbocharged inline-4 that makes 208 horsepower and 258 pound-feet of torque and a pair of twin-turbocharged 3.0-liter V-6s, both part of the VR family that replaces the aging, but still competitive, VQ naturally aspirated V-6. In base form, the 3.0 produces 300 hp and 295 lb-ft of torque. In the Red Sport 400, it churns out400 hp at 6,400 rpm and 350 lb-ft of torque all the way from 1,600 to 5,200 rpm.
The differences involve the turbochargers. On the 300-hp version, the turbos spin out 8.7 psi of boost. Turbine speed sensors on the 400-hp version allow the turbos to spin faster and create 14.7 psi of boost.
Of the turbo engines, we have only driven the 400-horsepower VR and it is a delight. It provides willing, easy power and lets out a muffled howl when pushed. Power is accessible across the rev range, making highway passing a breeze. Zero to 60 mph takes less than five seconds, probably around 4.8 with rear-wheel drive and as low as perhaps 4.5 with all-wheel drive. If you are looking for reasons to buy the Q50 Red Sport, this engine is it.
All engines are mated to a 7-speed automatic transmission with a manual mode and available shift paddles. The transmission provides nice throttle-blipped downshifts and remarkably little driveline shock.
The Hybrid is quite quick as well, with well-coordinated throttle response and 360 combined horsepower from a special version of Infiniti's 3.5-liter V-6 plus a 50-kw motor system. It uses a unique dual-clutch-pack hybrid system (with a dry clutch fore of the transmission and motor system and a wet clutch aft of it) that effectively smooths out both shift shock and transitions from one power source to the other. It allows the car to gently take off on electric power alone, as well as turn off the gasoline engine to "glide" along down gradual expressway downhills. And with EPA ratings of 30 mpg combined (and an observed 29 mpg over about 100 miles), it manages to boost real-world mileage in a way that Lexus's performance hybrid system can't.
There's one respect in which the Hybrid doesn't quite measure up, and that's braking. The last bit before a complete, gentle stop feels "muddy," but if you stop harder it's more precise.
