The following review is for a 2005 Model Year. There may be minor changes to current model you are looking at.

New features, fresh styling enhance performance luxury sedan.

Introduction

The Infiniti Q45 features new styling and more luxury equipment for 2005. It looks more aggressive than before, with new front and rear fascia, a restyled hood and grille, a new headlight design with integrated fog lights, a restyled rear deck, new LED tail lights, and new chrome trim. 

Everything about the Q45 is smooth and easy. It's balanced well for driving on twisting roads and it's very stable at high speeds. Yet the ride is smooth, even on bumpy roads. Its powerful V8 engine delivers excellent performance and makes a wonderful growl. The Q45 uses rear-wheel drive, like a BMW or Mercedes-Benz, for better handling. The five-speed automatic transmission has been re-calibrated on 2005 models for smoother acceleration and more responsive downshifts. The active damping suspension, previously optional, is standard on all 2005 models. 

Infiniti may not have the heritage of BMW or Mercedes, but it offers first-class appointments and craftsmanship. A DVD-based navigation system is now standard. A new system tightens the seatbelts during emergency braking, helping to optimize the position of the driver for emergency maneuvers and crash protection. 

Lineup

The Infiniti Q45 is a rear-wheel-drive sedan powered by a 4.5-liter twin-cam V8. This all-aluminum engine produces a very healthy 340 horsepower and 333 pound-feet of torque. The only available transmission is a five-speed automatic with a manual shift mode. 

Q45 comes in one trim level ($55,900), and it includes everything you'd expect in a flagship luxury car, plus a long list of high-end electronics. Active safety features are among them: electronic stability control (VDC), traction control (TCS), anti-lock brakes (ABS), electronic brake-force distribution (EBD), along with the electronically controlled active damping suspension. Also standard: tire pressure monitors, xenon high-intensity discharge headlights, DVD-based navigation, voice control for the climate control system, an eight-speaker, 300-watt Bose stereo with six-disc CD changer, heated front seats. The Q comes with P225/55VR17 all-season tires on titanium-finish cast aluminum wheels with a full-size spare tire. All interior surfaces are covered in rich textured materials, including soft leather and, for 2005, a darker shade of genuine bird's eye maple wood. 

Options are few: The Premium Package ($5,800) adds climate-controlled front seats, power reclining rear seats with seat heaters, rear-seat audio and climate controls, perforated leather seat inserts, Intelligent Cruise Control with Preview Braking, XM or Sirius satellite radio, rear sunshades (power for the backlight, manual for the rear-door windows), and new 18-inch, seven-spoke alloy wheels wearing 245/45VR18 all-season performance tires. Opt for the Premium Package with Chrome Wheels ($6,800), and you get all of the above plus seven-spoke chrome-plated wheels. The only other options are a set of 17-inch run-flat tires ($400), satellite radio as a stand-alone feature ($400), and some port-installed accessories. 

Walkaround

The Infiniti Q45 has presence, with styling that says big luxury. Grille, hood, and front and rear fascia are new for 2005, lending the Q45 a more assertive, if not downright aggressive, demeanor. 

The headlights are new, with integrated fog lamps and larger bulbs for high beams. The headlamps incorporate a revised version of the Q45's trademark circle of seven xenon low beams that look like a Gatling gun. The aggressive appearance of the headlamps suggests the ability to turn night into day. Infiniti claims they are among the world's most powerful; its low beams are bright and have a dispersion pattern designed for long-range illumination in a narrow beam as well as wide-angle illumination in the foreground. The pattern of the low beams is designed to reduce glare to oncoming drivers by cutting the beam sharply on the left side. A switch on the dash allows the driver to adjust the height of the beams, a feature we liked. 

Overall, the front view of the Q presents a handsome shape, a sweep, as if the lines were poured on. There's very little chrome. The wide-mouthed grille is fully but sparsely filled by four broad, horizontal slats with a bright Infiniti emblem in the center. Hungry-looking air intakes dominate the lower bumper. 

In profile, the Q45's long wheelbase and relatively short overhangs suggest solidity and efficiency at the same time. Its drag coefficient is among the lowest of any production car we know, at just 0.30. The roof seems to have more rake when viewed from the rear. 

The 2005 Q45 has a new rear bumper, deck lid, and LED taillights, the latter reminding us of the lights on the smaller G35, all accented by new fine-line chrome trim. The exterior modifications bring a new sense of power and athleticism to the Q, along with a stronger family resemblance to our other Infiniti performance vehicles. 

Interior

The Q45's plush interior is swathed in Italian leather and bird's eye burl maple, a darker wood than last year's trim. Our 2005 Q45 came in Graphite leather with sort of a reverse piping in silver on the seats. It was quite nice, though no one seems able to do black interiors as well as the Germans, so we prefer the tasteful Latte on this car. An interesting choice is the sporty Firebrick. 

Lots of glass, including the big sunroof, brightens the cabin by day. Cool, functional, white-on-black electroluminescent gauges come out at night. Two slightly retro touches add richness for 2005: white faces for the gauges, and genuine metal knobs for accessory controls. 

The seats are new for 2005, and have been contoured for a sportier feel. We found them quite comfortable. The driver gets 10-way power adjustments, including lumbar, great for long freeway trips. Eight-way power helps the front-seat passenger get comfortable. Both have a memory function. 

The climate-controlled seats (included in the Premium package) have a low-profile fan in the bottom to draw in cabin air. A thermoelectric device in the seat back heats or cools the air before sending it out through distribution channels in the seating surface. Controls for the seat heaters are on the inboard side of the seat bottoms. We found the seat fans nice for running errands on a particularly hot Southern California day; they'd be an even bigger relief on steamy summer days in the South, East Coast or Midwest. 

Big plush armrests and two sizes of concealed cup holders complement the firm seats. Infiniti is better than the Germans at cup holders. There's a hatch under the center armrest for flat things, below which lies another, deeper compartment. 

The center dash is dominated by the navigation system with a seven-inch LCD screen and climate and audio controls. Infiniti put a lot of effort into making its navigation system more useful. Among its features is a three-dimensional bird's-eye view, like looking down at an illustration of the ground from a hang glider. Like most navigation systems, it offers a choice of routes: shortest time, shortest distance, it can even point you to the nearest ferry, should you prefer to travel by sea. It will also tell you the location of the nearest ATM, hotel, restaurant or rest area. When running low on gas, it will ask you if you want it to find the nearest gas station, a feature we've found useful. A Previous button next to the toggle used to control some of the mapping functions gets you back to the previous screen, a very good feature. 

Shift into reverse and the screen displays what's behind the car, eyed by a tiny camera over the license plate. Unlike the video on shuttle buses, it's in living color. The backup lights aren't bright enough for the camera to work at night, and in the sunshine it's hard to see the screen. Still, this gadget can be useful for spotting children on tricycles, short posts and other objects you want to avoid. 

The climate controls use the screen as well and we found this to be fussy at times. To lower the fan speed, for example, you must press the Auto A/C button, then look at the screen to determine which of six buttons to press to lower the fan speed. Adjusting the temperature is easy: Simply turn a big knob on the left. Fortunately, there is an Off button to shut the climate control off. 

The stereo rocks. Operating it requires a little familiarization, however. The volume control is the big Audio knob on the right (rather than on the traditional left). Tuning stations is accomplished by a toggle in the center. Other functions demand pressing the big Audio button, then pressing the appropriate buttons indicated on the screen. (The map reappears after a few moments of inactivity.) Audio controls on the left side of the steering wheel help here. 

The new satellite radio systems can be great companions on long trips, delivering high-quality sound nearl. 

Driving Impression

Everything about the 2005 Infiniti Q45 is smooth and easy. The ride quality is smooth and sophisticated. The suspension levels out the bumps really well on a straight road. Unlike many European cars, there's no jostling or head toss here, even on bumpy roads. The speed-sensitive power-steering feels very light. 

Its handling is responsive. This car feels long and is indeed a couple of inches longer than a Lexus LS 430. Though it handles well, we had little doubt of its size when driving quickly on winding roads. Still, it's easy to control when the tires squeal, and when you pitch this big baby it stays with you. 

The active damping suspension (standard) can be set in Sport mode, but we couldn't feel much difference between the Normal and Sport modes when the driving was sporty. Normal mode was firm enough to be good in the twisties. But we did feel a big difference over sharp bumps. You don't want to be in Sport mode over potholes or at slow speeds. So we couldn't find much use for Sport. If Normal were softer, then having two modes would be more useful. 

Run-flat tires (17-inch only) are available ($400). Nissan says they can run 50 miles at 55 mph after a puncture. They might significantly change the feel of the ride, making it harsher, but this is speculation as we have not tried them out. Run-flat tires have very stiff sidewalls, but tire makers continue to improve the ride quality. The most responsive handling comes from the Premium version with its 18-inch wheels and tires. 

The engine and transmission are very responsive. The Q's V8 engine provides lots of power: 340 horsepower. That compares with 290 horsepower from a Lexus LS 430. The 4.5-liter V8 feels particularly strong starting at 3000 rpm. The mid-range response is great, with a whopping 333 pound-feet of torque at 4000 rpm. Its full-throttle upshifts at about 6500 rpm are exciting. A final-drive ratio of 3.13:1 adds to the Q45's lively character. The 32-valve, four-cam engine makes a wonderful growl, which you can mostly hear only with the window down. This is, after all, a luxury car. 

Shifting is silky smooth. The five-speed automatic transmission was very responsive, so we preferred to leave it in Drive. However, it does offer a manual mode: From Drive, push the wood-trimmed shift lever into a separate gate to the right, then move it fore or aft to change gears. The shifter engages with a satisfying click. The system is programmed to override the wishes of the driver when those wishes don't compute, however. 

The four-wheel anti-lock vented disc brakes are big, over 11 inches front and rear. The system includes electronic brake-force distribution (EBD), which balances front and rear brake force depending on the load. Passengers and cargo upset the brake balance in any car, as does the forward shifting of weight as the car stops, and EBD is designed to correct this, stopping the car quicker and more controllably. There's also Brake Assist, which reduces pedal effort under hard braking. Infiniti uses a simple mechanical system that reduces pedal pressure during panic stops when ABS is activated, unlike the German electronic systems that take over your brake pedal, presuming to know better than you what you want your car to do. Infiniti says that during testing of its system, stopping distances were reduced by more than 10 percent, which can make the difference between hitting and stopping before hitting the rear bumper in front of you. 

Vehicle Dynamic Control reduces power and applies the brakes at individual wheels when traction is lost at any wheel. We pushed the Q45 until the VDC corrected us, which it did subtly on a hard, sharp curve with loose gravel over pavement; we would have slid a few feet, but VDC caught the car. There's also a traction control system, which we liked better than the Mercedes-Benz system because it doesn't cut the throttle so radically or for so long. 

Intelligent Cruise. 

Summary

The 2005 Infiniti Q45 is a superb performance luxury sedan, with awesome horsepower, unique styling, quality appointments, and a long list of clever conveniences. It's sportier than the Lexus LS 430 and it's bigger and sportier than a Mercedes E-Class. The Q45 is smooth and sophisticated and a terrific companion out on the open road. 

New Car Test Drive editor Mitch McCullough is based in Los Angeles; Sam Moses contributed to this report. 

Model Lineup

Infiniti Q45 ($55,900). 

Assembled In

Tochigi, Japan. 

Options As Tested

Premium Package ($5,800) includes climate controlled front seats, power reclining rear seats with heat, rear-seat audio and climate controls, perforated leather seat inserts, Intelligent Cruise Control with Preview Braking, XM or Sirius satellite radio, rear sunshades, 18-inch alloy wheels, 245/45VR18 all-season performance tires; splash guards ($130).