BOSTON – The ’14 Infiniti Q50 isn’t a big leap forward over the G37 it replaces, but that’s not all bad.

It’s reassurance for loyalists that the very good Infiniti sport sedan they love has not been remade into something unrecognizable.

Yet, while the Q50 oozes style and performance, it borrows much of it from its predecessor, which Infiniti now says it will keep selling through ’15, to maintain a budget-priced entrant in the competitive lower-luxury segment.

Despite all the curvature in its body panels, inspired by Infiniti’s 2009 Essence concept, the Q50, cruising side-by-side with a few G37s here on I-95 North, retains the long-hood, short-trunk silhouette of its forerunner.

Yet, the Infiniti sport sedan’s character line is more pronounced now, twisting flat and wide about mid-door in the back, and its double-arch grille, while similar to the outgoing G37’s, is more upright and employs a wavy mesh pattern instead of flat chrome bars.

The Q50’s stance is lower, wider and sportier than the G37’s but keeps the same 112-in. (284-cm) wheelbase.

And the Q50 still is powered by the G37’s 328-hp 3.7L VQ, a V-6 that hauls butt, although a 3,500-rpm torque peak would be preferable to the current 5,200 rpm.

The high torque peak is amplified by the relatively fast upshifts made by the Q50’s 7-speed automatic transmission, which carries over from the G. Steering-wheel-mounted paddles allow for easy downshifting.

The VQ is the most honored engine in Ward’s 10 Best Engines’ history with 14 consecutive wins from 1995 to 2008. But Nissan has inexplicably denied the engine a complete redesign.

So the specs are the same as in the G37, although Infiniti officials say much updating has been done, including reworking the intake and exhaust systems.

Infiniti touts Q50 highway fuel economy that is better than that of the discontinued 2.5L, V-6-powered G25 grade.

The Q50 also is rated 3 mpg (1.3 km/L) better on the highway than the ’13 G37.

In the 3.7 grade, WardsAuto achieves 26.5 mpg (8.9 L/100 km) combined at an average speed of 38 mph (61 km/h), better than the 23-mpg (10.2 L/100 km) stated average.

Weight reduction and improved aerodynamics no doubt play the biggest role in these efficiency triumphs. The Q50 is 54 lbs. (24 kg) lighter and has a 0.03 lower drag coefficient than the outgoing G.

Available on the 3.7 grades and standard on hybrid Q50s is Infiniti’s steer-by-wire Direct Adaptive Steering technology, which electronically sends “driver input to the front wheels, where a high-response actuator drives the steering rack,” the auto maker says.

While some may take issue with DAS being called “steer-by-wire,” given there is a steering shaft present in case of catastrophic power failure, Infiniti says in normal operation a clutch disengages the mechanical linkage.

DAS is supposed to reduce all the minute steering corrections that many drivers do unconsciously, as well as filter out what Infiniti refers to as “dirty noise” vibrations.

DAS is designed to work in concert with another Infiniti technology, Active Lane Control.

Because of DAS, Active Lane Control uses steering, rather than braking, to keep the Q50 between the lines. But, like many camera-based lane-keeping systems, it loses vision in corners and will speed up until it once again tracks the vehicle ahead.

To avoid those alarming run-ups in speed when adaptive cruise control is on, ALC is best left for straight-line driving.

While the Q50 can’t steer itself, ALC does allow for automated steering corrections due to crosswinds or minor road surface changes.

The corrections take some getting used to, and yes, DAS is yet another in-vehicle nanny technology. But DAS and ALC are worthwhile because they can keep an inattentive driver from drifting into the next lane.

DAS allows for selectable steering modes, both for resistance and responsiveness. “Heavy and quick” is our preferred setting; “standard and standard” and “light and casual” are other combinations.

As with similar systems, differences between settings are slight. “Heavy” and “standard” feel similar, with “light” being only a smidge lighter than either.

Unlike the G, the Q50 offers a hybrid option, in the form of the Infiniti’s Direct Response Hybrid system with Intelligent Dual Clutch Control, which mates a 302-hp 3.5L VQ V-6, lithium-ion battery and the brand’s 1-motor/2-clutch control system seen in the larger ’13 M hybrid.

The electric motor generates 67 hp and 214 lb.-ft. (290 Nm) of torque on its own, and total system horsepower is 360.

Infiniti calls the hybrid the Q50’s most powerful engine option and not an effort to gain any eco cred.

Still, our real-world fuel economy in the hybrid is a respectable 34.8 mpg (6.8 L/100 km), above the 31-mpg (7.6 L/100 km) average projected. Also impressive is the frequency the car travels on electric power alone, even at highway speeds.

The G had been criticized for having too harsh a ride, but the Q50’s is almost too sedate. Hitachi’s Dual Flow Path shock absorbers on the rear multilink suspension, and which already were available on the ’13 G coupe, lower damping force relative to piston speed to compensate for minor road undulations. But the bounciness gave the G some of its character.

The Q50 is another feather in the cap of Infiniti’s interior designers.

Quality, well-detailed materials are abundant in our Q50 3.7 and Q50 Hybrid Premium test cars.

Fashion-forward design elements include the asymmetrical, swooping aluminum trim of the center stack, another nod to the Essence concept.

This car’s cabin, however, is not as showy as recent Infiniti interiors. Perforated leather seats and door trim lend sporty flair, but the features are subtler than the wavy-embroidered seats in the JX cross/utility vehicle.

The chic aluminum trim, embossed with tiny dots, recalls chain mail worn by Japanese warriors.

Our pre-production testers have excellent fit-and-finish, even in hard-to-see areas such as where the headliner meets the windshield.

Aluminum trim appears in all Q50 models, but leather is standard only on sport grades.

Front seat comfort is disappointing due to soft foam and minimal contouring; thigh bolstering is lacking, too. In the back row, outboard seating positions are reasonably comfortable, but headroom is tight in all three spaces.

Infiniti engineers managed to make the Q50 feel less cramped than the G by thinning out the B-pillars to bring in more daylight. In doing so, the car’s rear foot wells now are less of a black hole.

But after being in the Q50, it’s hard to imagine five, or even four, occupants sharing space in the future Mercedes CLA-based Infiniti compact sedan.

Even with the carryover 3.7L and soft seats, the Q50 is a respectable sport sedan, as was the G.

Infiniti’s problem with the predecessor was on the marketing side and not due to any mechanical shortcomings. The Infiniti lacked the gotta-have allure of the BMW 3-Series, the segment’s perennial best-seller, which outsold the G37 by 40,000 units in 2012.

To match BMW, Audi and other luxury brands, Infiniti needs more Q50 variants, such as the forthcoming turbocharged 4-cyl. model with an 8-speed automatic. Partner Mercedes-Benz is supplying the engine.

The 3.7 and Hybrid grades are a good start; a coupe is expected and a convertible makes good sense after the G has left the market.

cschweinsberg@wardsauto.com

 

’14 Infiniti Q50 3.7
Vehicle type 4-door, rear-wheel-drive, 5-passenger sedan
Engine 3.7L DOHC V-6; aluminum block/heads
Power (SAE net) 328 hp @ 7,000 rpm
Torque 269 lb.-ft. (365 Nm) @ 5,200 rpm
Bore x stroke (mm) 95.5 x 86.0
Compression ratio 11.0:1
Transmission 7-speed automatic
Wheelbase 112.2 ins. (285 cm)
Overall length 188.3 ins. (478 cm)
Overall width 71.8 ins. (182 cm)
Overall height 56.8 ins. (144 cm)
Curb weight 3,574 lbs. (1,621 kg)
Base price $36,700 plus $925 destination charge
Fuel economy 20/30 mpg city/highway (11.8-7.8 L/100 km)
Competition BMW 3-Series, Audi A4, Mercedes-Benz C-Class, Lexus IS, Cadillac ATS, Acura TSX
Pros Cons
Lovely interior Too familiar exterior
328-hp V-6 standard Same output as in G37
Hybrid option Needs more variants