Review

The Infiniti G25 is a new entry-level model using a 2.5-liter V6 engine in place of the 3.7-liter V6 used by all the 2011 Infiniti G37 models. Also new for 2011 are high-performance IPL coupes from the Infiniti Performance Line. Also new is the 2011 Infiniti G37 Coupe AWD Sport, an all-wheel-drive coupe with sports suspension and high-performance brakes. A new 2011 G37 Limited Edition convertible comes fully loaded and features unique trim.

All Infiniti G models get subtle styling upgrades for 2011 giving them the look of a sports package, while Sport models get an even more aggressive look.

The Infiniti G sedan, coupe, and convertible are easily distinguished from one another by their styling. But they all have similar exterior dimensions and an identical wheelbase (the distance between the front and rear wheels). All share the same chassis, and their basic structure is shared with the Nissan 370Z, which has a shorter wheelbase.

The Infiniti G37 sedan, coupe and convertible models deliver performance comparable to the 370Z. Nissan excels at these V6s and the G37's 3.7-liter V6 engine is more powerful than what's found in the engine bays of many competitors. And it's calibrated for the response and excitement that enthusiast drivers prefer. The G25 isn't as fast as the G37, but we found it delivers similar driving dynamics at lower operating costs.

While the sedans offer five-passenger seating, the coupe and convertible models offer sex appeal. All-wheel drive is available for greatly improved traction in snow and rain, helping tame the power these cars can otherwise deliver to their rear wheels.

The Infiniti G shares many mechanical components with the Nissan 370Z sports car on a longer platform, so the sporting character should come as no surprise. Performance has never been an issue with the G, and the interior finish and refinement continues to improve.

All Infiniti G models come standard with rear-wheel drive, which delivers handling characteristics front-wheel drive rarely matches. The standard 7-speed automatic transmission available on all G37 and G35 models is tuned for sporting response, with available steering wheel paddles for semi-manual shifting. All models except the G25 are available with a 6-speed manual transmission, a feature that's increasingly rare in this class.

The Infiniti G has all the features expected in this category, including leather upholstery, superb audio, and HID headlamps. The navigation system monitors traffic conditions, provides restaurant advice from Zagat and includes a 9.3-gigabyte hard drive with a memory-card slot.

The four-door G is Infiniti's best seller, and a true sports sedan, reacting to driver commands in the fashion of a sport coupe. Yet it seats four comfortably in all circumstances, with easy in-out access and plenty of stowage space in the trunk. The V6 delivers 328 horsepower and 269 pound-feet of torque in the sedan.

The two-door Infiniti G37 coupe looks racier than the sedan. Rear-seat room is restricted, however, and adults will not be happy in the coupe's back seat for long. Instrumentation is first rate, and climate, audio and navigation systems are easy to understand and control. The coupe's engine delivers slightly more power (330 hp, 269 pound-feet of torque) and the convertible 325 hp.

IPL coupes add 18 horsepower, a more aggressive exhaust note and crisper handling relative to a G37S coupe. The IPL, or Infiniti Performance Line, is offered with both transmissions but not all-wheel drive.

The Infiniti G37 convertible looks a lot like the coupe until a button on the console is pressed. Then it becomes a wide-open cabriolet in about 30 seconds, its three-piece hardtop folding into the rear. The convertible features a Bose Open Air sound system that automatically adjusts audio levels according to vehicle speed and ambient noise. Its climate control system adjusts fan speed based on vehicle speed when the top is open.

The 2011 Infiniti Limited Edition models come loaded and include unique trim and features inside and out. An exclusive Monaco red leather is available only on a Malbec Black IPL coupe, which is painted a black-cherry metallic hue.

Infiniti G models compete with the Lexus IS, Acura TSX and TL, BMW 3 Series, Mercedes C-Class, Saab 9-5, and Audi A4 and A5. The Infiniti Gs generally deliver better performance and handling or more equipment or both for less cash.

Line-Up
The 2011 Infiniti G is available as a four-door sedan, two-door coupe or two-door convertible in a total of 19 variations. All except the G25 are powered by a 3.7-liter V6 of 325-348 hp, with either a 7-speed automatic or 6-speed manual transmission; the G25 uses a 218-hp 2.5-liter V6 and 7-speed automatic only. All-wheel drive is available on G sedans and coupes.

The G25 sedan ($30,950) includes leather upholstery, power front seats, aluminum trim, climate control, power windows/locks/mirrors, Intelligent key, tilt/telescoping steering wheel, 17-inch alloy wheels, bi-xenon headlamps, fog lamps and XM radio. The G25 Journey ($32,350) upgrades to dual-zone climate control, rearview monitor, auto on/off headlamps, heated front seats and mirrors, eight-way power passenger seat, USB/iPod, HomeLink and Bluetooth. A moonroof ($1,000) is optional. The G25x Journey ($33,950) adds all-wheel drive.

The G37 Journey ($35,050) has everything on the G25 Journey plus a 328-hp V6. The G37x ($36,650) adds all-wheel drive. Options include the Technology package ($1,200) with intelligent cruise control with preview braking, advanced climate control, pre-crash front seatbelts, rain-sensing wipers; the Premium package ($2,150) with Bose audio, moonroof, driver memory, power tilt/telescope, rear park sensors; 18-inch performance tires and wheels ($500); navigation ($1,850); Maple cabin trim ($600). A Sport package is available for the G37 ($2,150) and G37x ($1,150) that duplicates a G37 Sport model without manual gearbox.

The G37 Sport sedan ($39,450) is the only G sedan with a manual transmission, and it comes with sport-tuned suspension, upgraded brakes, revised steering, viscous limited slip differential, 18-inch wheels with high-performance tires, and more aggressive front end styling. The G37 Sport also comes with 12-way power sport seats, driver memory system, power-adjustable steering column, aluminum pedals, a moonroof, navigation, and the Premium package with Bose Studio on Wheels audio with 11 speakers and a 2.0GB hard drive, driver memory system, climate controlled front seats with a cooling feature and rear sonar back-up warning.

A G37 Sedan Sport Appearance edition ($39,200) adds a front chin spoiler, rear decklid spoiler, unique 9-spoke 18-inch alloy wheels, power moonroof, Infiniti Studio on Wheels Bose audio system and 2.0GB Music Box. The G37x Sedan Sport Appearance edition ($40,800) adds all-wheel drive.

The G37 Limited Edition ($43,400) and G37x Limited Edition ($44,000) sedans feature unique 18-inch alloy wheels, midnight-black grille, Monaco red leather, moonroof, Bose sound system, navigation, all the Sport model chassis and seat upgrades (including solid magnesium paddle shifters), and unique front trim and headlights.

The G37 coupe ($36,050) is equipped similarly to the standard sedan, though it comes with 18-inch wheels; there are no options. The G37 Journey coupe ($37,650) and G37x Journey coupe ($39,300) also mirror the sedans as do factory option choices; some packages cost more than the comparable sedan package and the Journey coupe offers an aerodynamic package ($3,950).

The Infiniti G37 Sport coupe ($42,400) gets the 6-speed manual and all the performance hardware described above for the Sport sedan and comes standard with the Navigation, Premium, and Sport packages. The aerodynamic package is an option.

The Infiniti G37 IPL coupe offers a choice of manual ($47,950) or automatic ($49,850) and features revised engine and exhaust tuning for 348 hp, stiffer springs and dampers, red stitching on seats and steering wheel, unique front bodywork, and 19-inch wheels. It's offered only in Graphite Shadow or IPL-exclusive Malbec black paint with dark gray or, on Malbec only, Monaco red leather. The IPL also gets special aluminum cabin trim.

The G37 Convertible ($44,500) has a power-retractable steel hard top that opens or closes in about 30 seconds and standard back-up camera. It's equipped and optioned similarly to G37 Journey coupe but offers options of a Bose Open Air Sound System that adjusts audio levels based on outside noise, vehicle speed and top position, and a spare tire. The Convertible Sport 6MT ($48,950) is equipped like the other Sport models and now come standard with navigation. The Limited Edition convertible ($56,750) carries exclusive pieces and Monaco red leather. There is no IPL convertible but a concept of such a car was shown at the 2010 Paris auto show.

Safety features on all models include two-stage front airbags, side-impact airbags for front passengers and front and rear side-curtain airbags on sedan and coupe, and door-mounted front-side curtain airbags on convertible. The electronic stability system is dubbed Vehicle Dynamic Control. The convertible has pop-up roll hoops behind the rear seat for rollover protection. All-wheel drive can enhance safety in adverse conditions with more stable handling.

Walk Around
The G37 sedan was last redesigned for 2007, and it gets a bit of mid-cycle freshening for 2011. Essentially what was sport-package front and rear styling is standard for 2011, and the Sport models get a more aggressive look and updated wheels.

Coupe and convertible models receive the same sport-package treatments for 2011, and the fog lights on the 2011 coupes have been relocated to the lower grille openings as they were on the 2010 sedan. All Gs share Infiniti's affinity for wave shapes in the aluminum hoods.

The new IPL coupes are even sharper at the lower extremities. The front spoiler is deeper and more square at the edges and we foresee many being remodeled on curbing or steep driveways. At the tail, eyes are drawn to a pair of tailpipe barrels almost five inches in diameter.

Despite the differences in styling, the Infiniti G sedan, coupe, and convertible have similar exterior dimensions and an identical wheelbase (the distance between the front and rear wheels). All share the same chassis, and their basic structure is shared with the 370Z other Nissan and Infiniti.

The current, second-generation Infiniti G models are swoopier than the pre-2007 versions though bulkier around the shoulders and hips. From the side or three-quarter view the coupe and convertible share a mild family resemblance to the shorter, chunkier Nissan Z-car.

The Infiniti G cars have a striking look not often mistaken for anything else. The front wheel cutouts are larger than those on earlier models, leaving less metal for the fenders and making them appear to rise even more. The headlight clusters are loaded with separate lenses, yet they're smaller and sexier. Infiniti calls the aluminum hood a wave hood, although the sea looks pretty flat between the bulging shorelines of the fenders.

The G37 convertible has a power folding-mirror function that pulls the side mirrors up against the glass at the driver's request. The convertible has a unique design from the windshield pillars rearward. It's slightly wider than the other G models, with a modified rear suspension that allows for the top's power mechanism and stowage space behind the rear seat. The convertible has more heavily reinforced windshield pillars, side members and body sills, which help reduce body flex and vibration when motoring with the top down.

When its three-piece steel top is closed, the convertible looks much like the G37 coupe. Its heavily insulated headliner works almost as well as the coupe's fixed roof at keeping ambient noise outside the car. The top takes approximately 30 seconds from start to finish to open or close, initiated with the touch of a button on the center console. The Sport package gives the convertible a special, more aggressive looking grille and front end.

The factory wheel designs for the 2011 Infiniti G models are handsome. The standard 17-inch wheels on sedans feature a new five-spoke, triple-fork design. The massive 19-inch wheels that are optional fully complement the car's looks.

Interior
Improvements inside the 2011 Infiniti G37s are subtle, but welcome, and they point to a steady trend over the last several model years. The overall quality of the G passenger cabins has increased steadily. They're much better suited to the luxury class than they once were and lean toward contemporary design than traditional wood and warmth.

Generally, the G interior is lively and friendly without being fussy or overly busy. There are features aplenty, tempered by a focus on function and connecting the driver to the car. The materials, fit and finish are good, though we are still not enamored with the graining on some of the harder plastics.

Getting in and out of the G is easy with the four-door sedan, and a bit more difficult with the coupe and convertible, particularly if your driveway has a significant slant. The doors on the two-door models are long and heavy. The slightest incline can make it difficult to lock them in the open position, and they want to fall closed.

The perforated leather seats are comfortable, and the standard eight-way driver's seat has adjustable lumbar support. The Sport Package seats have more adjustment and bigger bolsters on the back and bottom cushions and are fully capable of containing the driver while exploiting the car's winding road capabilities.

The three-spoke steering wheel is wrapped in hand-stitched perforated leather, with audio and cruise control buttons on its spokes. Optional paddle shifters for the automatic transmission are magnesium, and they are attached to the column and not the wheel so their position never changes. That isn't the case with many cars, where shifting during busy maneuvers can be difficult. We like the shift sequence, too. You pull back on the right paddle for upshifts, and on the left for downshifts.

The dashboard and center console design is the same in all G body styles, with slight variation in the front door-panel designs. The dash applies Infiniti's double wave theme, and the company's signature analog clock sits front and center in the center stack of controls. For 2011, the revised aluminum trim is called Shodo, inspired by the traditional art of Japanese calligraphy, and it's elegant. Yet the subtly etched Silk Obi aluminum in our convertible test car might be the most beautiful metal trim we've seen. A high-gloss maple trim is optional in all models, while special editions may have red-tone maple.

The Gs new gauges feature electroluminescent lighting: white needles and numbers on a black background with violet highlights. An easy-to-read information display shows useful trip functions such as fuel mileage, average speed, elapsed time, running distance and distance to empty, as well as outside air temperature, odometer, and warning displays; the switches for this display are on the sides of the instrument hood.

The center stack falls from a high-resolution LED screen that displays climate and audio data or navigation information. The stereo and climate controls are located out in the open below the information screen, with our preferred layout of audio on top and climate below. The design is attractive and very good from the functional perspective, though some would prefer the knobs for volume and temperature were larger or not identical.

The navigation system is controlled by a mouse-like knob below the screen, by touching the screen itself for some functions, or by voice commands. Infiniti's point-and-click device is one of the more effective, least cumbersome interfaces in the luxury class, but it's still more difficult to use than the best touch screens.

The nav screen itself is quite sharp. The map offers a bird's-eye view, which gives a perception of distance by incorporating a horizon and, depending on the available mapping data, three-dimensional building footprints for the local surroundings. It's neat to look at, though many testers prefer the regular overhead view. The XM satellite radio system provides real-time traffic updates on the screen, where available, and the Zagat restaurant guide to the navigation software.

The standard sound system is competitive with that in any luxury sedan. The upgrade Bose Studio On Wheels audio delivers a sound that's richer, fuller, more intricate and crisper than many systems in cars costing thousands, sometimes tens of thousands of dollars more. We stepped directly from a G into a $100,000-plus European sports coupe with that marque's top-level sound system and could not distinguish a difference between the two.

The upgrade audio in the convertible is called Bose Open Air, and it's standard, with an extra pair of speakers in the front headrests, right behind the ears. It adjusts volume and re-mixes the audio in real time according to ambient noise. The available 9.3 gigabyte hard drive will compress and copy about 90 CDs in short order. The audio directory can access music by artist or type.

The G37 Convertible comes with an adaptive climate control system that automatically adjusts airflow and fan speed based on top position and road speed. Lots of rear glass makes for good rearward visibility, even without the optional back-up camera. Both the sedan and coupe have quite good outward visibility.

The front door pockets are small in all G models, half-taken by armrests, although each includes a hollow for a water bottle. There are also two cupholders behind the shift lever. The center console has been redesigned, and cubby storage includes a respectably sized glove box. The back side of each front seatback has a magazine pouch (unless you order the cooled seats). Two cup holders pop out of the fold-down, rear seat center armrest, which also has a unique compartment masked by a Velcro-type flap on the right side.

Interior roominess is competitive for the class. The G sedan's wide rear door openings leave room aplenty for legs, knees and feet when getting in and out of the back seat.

The coupe is a different story. Headroom and legroom are compromised by 4 to 6 inches. The driveshaft hump runs high between the two rear seats, and there's a wide crack between the seatback and seat cushion that might get uncomfortable over the miles.

Rear seat space in the G37 Convertible is just as tight. Access in both coupe and convertible is at least eased by a power walk-in device with position memory. In both, the front seatbacks tilt forward with a lever and then move forward automatically at the touch of a button to ease entry/exit. In either two-door the rear is suitable only for kids or smaller adults.

With 13.5 cubic feet of trunk space, the G sedan slightly surpasses the cargo space offered by the Lexus IS and BMW 3 Series but falls well short of the Audi A4 (17 cubic feet).

The coupe fares worst of all in trunk space with 7.4 cubic feet and no hatchback versatility. A folding rear seatback improves things by allowing larger items to flow from the trunk into the passenger space, and it explains that notable crack between the back and bottom cushion when the rear seatback is upright.

The G37 Convertible offers competitive trunk space when compared with other cars in the class, with 10.3 cubic feet, but only with the roof up. With the top down there is two cubic feet of space so the open-top trunk becomes the back seat. So on longer trips, you may be forced to keep the top up. The convertible's top works easily and without a hitch, but we wish it would operate when the car is rolling at moderate speeds (up to 15-25 mph), as the tops do in many convertibles.

Driving Impressions
Sporty handling and a willing engine make the Infiniti G models exhilarating to drive. Relative archrival Lexus, the G maintains Infiniti's stance a car is first and foremost to be driven. And a G with a Sport or IPL package has a performance edge, a rawness, that sets it apart.

Where the G has come up short is in the smoothness, finish and refinement of a luxury car. To Infiniti's credit, it has incrementally but steadily addressed the problem, to the point where the G line stands on better footing, perhaps not quite Lexus levels of quietness but competitive.

The newest G and arguably the best value is the G25. It uses a smaller and smoother 2.5-liter V6 engine to lower the price and weight, increase the fuel economy, take some weight off the nose for crisper steering input and for most North American drivers on U.S. roads the 218 horsepower will be more than sufficient. The G25 7-speed automatic has closer gear ratios than in G37 automatics to get the best out of the smaller 2.5-liter engine. We had no trouble passing slower traffic or merging on the fastest expressways in the G25. By virtue of its smaller dimensions the engine is smoother than the big V6 in G37s, and while the Lexus IS250 is more refined, it doesn't seem as sporty as the G25.

On the open road the G cruises comfortably, quietly and so stable that little driver input for steering correction is ever needed. The suspension is taut and compliant, not nearly as soft as many mid-luxury models, and even the sport package is forgiving enough to drive daily. Only big, sharp bumps transmit any ruckus to the cabin, which is magnified on sport packages because of the lower profile tires, but that might help you avoid ruining them on potholes.

There's little wind noise even at extra-legal speeds. There's more road noise from the larger tire packages than from the standard treads. However, we preferred the added grip and sharper looking appearance of the 19-inch wheels; even with tire replacement costs figured in, we think they're worth the extra cost.

All G37 models are equipped with the same 3.7-liter V6, though the output varies from 325-348 hp. These engines are not turbocharged so they make their best power at higher revs, and they're big enough that midrange is more than sufficient to get the job done briskly. Though they rev to 7500 rpm, they are not as smooth about it as the earlier 3.5-liter.

In a 3700-pound car, 328 horsepower delivers strong acceleration. Stand on the gas and the 3.7-liter V6 willingly and heartily rev to levels normally associated with smaller, less complex engines, right up to maximum rpm. And the character is as important as sheer performance. In contrast, BMW's turbo 3-liter brings 300-plus horsepower and better torque for urban driveability, Audi's 2-liter turbo makes almost as much torque but not the revving horsepower, and Lexus' and Acura's 3.5-3.7 liter V6s deliver 300-306 hp, with torque similar to the G37's.

On IPL coupes, the exhaust is genuine dual from the engine back and the electronics have been retuned to extract 348 hp, the additional 18 all coming at the upper end of the tach. It also makes a deeper low-rpm purr than the standard car while maintaining the distinctive banshee howl from midrange up.

The 7-speed automatic transmission allows brisk acceleration, with two overdrives for more relaxed highway cruising. It does its job casually at part-throttle and briskly when you're in a hurry. If the driver moves the stubby leather-wrapped shift lever to the left, however, Sport mode is engaged. The upshifts come at higher rpm, upshifts and downshifts are quicker, it rev-matches downshifts, and it downshifts automatically under moderate-to-heavy braking. You can also choose gears manually using the floor lever or shift paddles on models equipped with them.

While the G's 7-speed automatic is excellent, we still like the conventional 6-speed manual. Gear selection is precise, requiring moderate effort in keeping with the performance nature. Clutch operation is heavier than we expect in a sport coupe, heavier than in a Honda, and more in line with a V8-powered muscle car, but the engagement is easy to modulate so traffic jams aren't an unbearable nuisance. (Unlike the Z-car the G manual does not automatically blip the throttle at downshifts, which most enthusiasts switch off anyway.)

The IPL coupe is the sportiest G37, a step beyond the Sport-package coupe. Spring rates and dampers are firmed up 20 percent in front and 10 percent in the rear, while steering, tires, brakes, differential, the rest of the mechanicals, are sport-package grade. The firmer spring rates add control without making the ride feel anywhere near 20-percent harsher. We think the IPL is sufficiently compliant to serve as the standard sport package. The IPL is meant to add performance without going as far (and pricey) as BMW's M, Mercedes' AMG, or Lexus' F divisions, which they've done.

A G37 convertible feels like a sports car because of the wind in your hair and exhaust note filling your ears, but it's not as sporty in terms of outright performance as the coupe or sedan. There are two primary reasons: One, when you take the top off a car that does not have a separate frame (like some exotics) the body loses some of its stiffness, which means the suspension can't be as precisely tuned because the structure it's bolted to isn't as rigid. With the top up in a G37 convertible you'll hear this on twisting driveway entries as the roof sections move against their rubber sleeves ever so slightly, and top down, the windshield will shudder more on rough roads, an effect you can easily see by glancing at the rear view mirror.

The other reason a convertible doesn't perform as well as a coupe is weight. The power folding hardtop apparatus and the additional body framing added to improve rigidity add weight. In fact, a G37 convertible is more than 450 pounds heavier than a G37 sedan. Long before cars were around, Newton figured out the laws of equal and opposite reactions, and 4100 pounds simply doesn't change direction as quickly and easily as 3700 pounds do, all other things being equal. The G37 convertible offers the same nice steering, engine and transmissions as the coupe, but is better suited to touring than race tracks.

The front-midship layout of the G, with the engine set farther back behind the front axle, is inherently well balanced. The G has a planted, sure-footed feeling that comes from proper tuning, not extra weight or electronics masking inherent deficiencies. On any G with the Sport package, the speed-sensitive power steering is seamless. It turns precisely into corners, with no dead spots through a long curve, and is sensitive enough to feel and make very small changes.

The G37 Sport Coupe 6MT is so good it almost has a downside. Pushing harder, over remote, twisty, smooth curves, we felt the standard limited-slip differential and stability electronics (VDC) at work. Or rather, we saw the VDC working thanks to a light on the dash. The corrections are beautifully subtle. You can pitch the G37 to a ridiculous point, and the VDC just gently won't allow the car to get out of shape. It doesn't tell you how wrong you were, by cutting engine power for too long, like some electronic stability controls do.

The brakes are smooth, predictable, and the car is rock steady under heavy braking, inspiring confidence in any driver. They're also sensitive, and when you jump on them they grab, so it takes a little time to develop the technique for smooth application. The G37 Sport models come with bigger brakes than the others for less fade in repeated hard applications.

Infiniti's ATESSA E-TS all-wheel-drive system monitors data such as wheel spin, throttle position and vehicle speed, and automatically diverts up to 50 percent of the engine's power to the front wheels, improving traction and control when road conditions are less than optimal. Yet in ideal conditions, when the road is smooth and dry, the all-wheel-drive system still sends all of the power to the rear wheels, preserving the G's sporty rear-drive handling characteristics.

Summary
The Infiniti G sedans, coupes and convertibles are to some extent luxurious, four-seat versions of Nissan's 370Z sports car. All the G models excel at driving dynamics. The interiors are friendly and feature-laden without being too busy. The Gs are priced lower than most comparably equipped European competitors. We think they're a good choice for performance-oriented drivers.

NewCarTestDrive.com correspondent J. P. Vettraino reported from Detroit, with Sam Moses in the Columbia River Gorge, Tom Lankard in Lenox, Massachusetts, and G.R. Whale in Northern California.