The bionic cheetah.

Introduction

The Infiniti FX is an SUV for people who like to drive. Both the V6-powered FX35 and the V8-powered FX45 give the enthusiast SUVs from Mercedes-Benz, BMW, and Porsche a run for the money, particularly your money, as the Infiniti models cost less than the German competition. Yet in terms of acceleration and handling, they give up nothing to the Europeans. The FX drives more like a big sport coupe than a truck-based SUV because it is more like a big sport coupe. 

Both Infiniti models are exciting driver's cars, smooth, powerful, very stable. They can be driven much harder than traditional sport utilities, thanks to their big, powerful brakes and firm, fully independent suspensions. On the highway, they feel planted and much more confident than traditional SUVs. The V6 engine that powers the FX35 is the same engine used in the Nissan 350Z sports car. It's powerful, giving the FX35 responsive performance. While driving the FX35, we never found ourselves wishing for the more powerful FX45. 

In fact, both FX models are based on the same rear-drive mechanical platform as the Nissan 350Z and Infiniti G35 coupe. They are not based on any Nissan truck, nor, as some folks seem to assume, on the similarly sized Nissan Murano SUV. (The Murano shares its front-wheel-drive architecture with the Nissan Maxima and Altima.)

Deriving an SUV from a sports car, however, does lead to some compromises. While the BMW X5, Mercedes-Benz M-Class and Porsche Cayenne each deliver varying levels of off-road capability, all are better suited for the rough stuff than the FX. Infiniti designed the FX primarily for on-road performance, with an available all-wheel drive system intended primarily for improved handling and performance in the snow. Although beefed up a bit for SUV duty, its chassis is still not as heavy as that of a true off-road truck, and that of course reduces the weight its powerful engines have to move. 

Infiniti also equipped the FX with enormous (optional) 20-inch wheels and tires; race car-sized brakes; and a tight, handling-tuned suspension. The goal was to make the FX as fun to drive as a sports car; Infiniti achieved that, with compromises in ride comfort, space and rock-climbing ability. The end result is a car-based crossover SUV that's full of character and exciting to drive on sports-car roads, but also one that has a stiff ride, a tighter cockpit than some of its competitors and flamboyant styling. But that may be just the thing for committed sports-car enthusiasts who need to lug their winter toys through the snow belt. 

FX was launched for the 2003 model year. 2004 brought some upgrades. Safety is enhanced for 2005 with roof-mounted supplemental side-curtain airbags as standard equipment, which provide rollover protection for both front- and rear-seat occupants. Also new for 2005: optional intelligent cruise control, and a Lane Departure Warning system, the first of its kind on a U.S. passenger vehicle. 

Lineup

The 2005 Infiniti FX is available as two models. The FX35 ($34,750) is powered by the 280-horsepower 3.5-liter V6 from the Nissan 350Z sports car, and comes with rear-wheel drive. An all-wheel version ($36,250) is also available. 

The FX45 ($45,250) adopts the 315-horsepower 4.5-liter V8 from the Infiniti Q45 luxury sedan. It comes only with all-wheel drive. 

All come with a five-speed automatic transmission, dual-zone climate control with microfiltration, power front seats, split folding and reclining rear seats, tilt/telescope steering wheel, high-intensity discharge (HID) headlights, and a long list of electronic and safety features, including electronic stability control. 

The FX45 gets a firmer suspension; 20-inch wheels as opposed to 18-inchers; leather heated seats and trim; a power tilt/telescope steering wheel; and memory for the driver's seat, mirrors and steering wheel. The Premium Package ($2,500) adds a power sliding glass sunroof, 300-watt 11-speaker stereo with steering-wheel controls and a six-disc CD changer, automatic headlights and a HomeLink built-in garage door transmitter. 

The FX35 can be loaded with the FX45's luxury features with the Touring Package ($2,900), which includes leather-appointed seating surfaces, heated front seats, the 11-speaker Bose system and a long list of other features. The FX35 Sport Package ($1,950) adds the 20-inch wheels, the stiffer suspension and aluminum pedals. To answer your question: With the Sport and Touring packages, an all-wheel-drive FX35 is equipped identically to a Premium Package FX45, without the V8, for $6,650 less. 

Both FX models offer a Technology Package ($4,200) that includes a GPS navigation system, a security system that allows the owner to unlock and start the vehicle without the key, traffic-sensing cruise control, and a rear-facing camera to assist backing up. A rear-seat DVD viewer is now bundled ($1,750) with the Lane Departure Warning system. A satellite radio receiver (XM or Sirius, $400), tow hitch ($600), roof rail crossbars ($240-$340) and 20-inch chrome wheels ($1,600) are also offered separately. 

Safety features that come standard include: dual-stage front airbags, front side-impact airbags, full-cabin curtain-style airbags, front seatbelt pretensioners and load limiters, active front head restraints, a sophisticated anti-lock brake system with electronic brake proportioning, and electronic stability control (VDC). 

Walkaround

The Infiniti FX presents wild styling with monster wheels. BMW's hottest X5 also comes with 20-inch wheels, but on the curvy FX they look disproportionately larger. The FX35 comes standard with 18-inch wheels, which are larger than what you'll find on most SUVs. Once you get used to the monster wheels, Infiniti's bionic cheetah styling begins to sink in. 

The Infiniti design team wanted to blend a substantial SUV lower body with a sleek, elegant upper body more reminiscent of a classic sports car or GT. In other words, the FX is supposed to look like a sports car from the beltline up. It does, sort of. 

Its proportions are certainly striking, starting with a wide stance and long hood under the tucked-tight roof. The overhangs are short, exaggerating the distance between its front and rear wheels. An oversized grille greets oncoming traffic, and the bulging hood looks high. A peek underneath the hood suggests it doesn't need to be, as the engine is tucked well below. 

For 2005, a darker chrome grille, and darker accents around the headlights and taillights help visually distinguish the FX45 and Sport Package FX35 from the standard FX35. 

The engine in the FX sits behind the front axle, giving the base V6 rear-wheel-drive model a near-optimal weight balance of 52 percent front, 48 percent rear; which in turn improves overall handling balance and reinforces the FX's road-burning feel. Even the protruding, stylized taillights have function beyond their looks. The lip of the lights that extends past the rear hatch adds aerodynamic downforce on the rear end, like a spoiler. Order the polished chrome wheels and you will, undoubtedly, have one of the most attention-grabbing SUVs on your block. 

Interior

When you climb into the driver's seat, you're coddled by the console and instrument panel. It's more sporting and more intimate than you might expect, but it also feels like a tighter fit than you'll find in most other SUVs. The overall impression is of a great luxury sport wagon. 

The front seats are comfortably firm, like those in a good European sedan, but the adjustments may require quite a bit of fiddling before you're set (that's why they invented seat memory). The driver's seat allows three inches of vertical travel, so you can perch up high to keep tabs on the rest of the tall SUV commuters around you, or drop down toward the floor for serious driving on challenging roads. 

The view over the FX hood reminds us of that in a Jaguar, with the metal sloped and contoured over the headlights and grille. It's the opposite of the squared-off hood of a BMW X5 or Range Rover, as if the FX is trying to tell you you're in a car rather than a truck. The view in the mirrors is not hindered by the fat, sloping rear pillars. 

The optional rear-view camera displays an image of what's behind the vehicle on the seven-inch dashboard monitor, with two virtual lines that correspond to the width of the FX. It's a great aid for checking behind the vehicle before backing out of a driveway or shopping center parking space, helping to ensure no people or objects are back there. 

Infiniti's designers wanted three separate interior zones intended to meet the needs of various FX occupants, the driver zone, the comfort zone and the play zone. The driver zone is designed to be like a cockpit. The steering wheel and instruments remind us of those in Nissan's 350Z sports car, with a thick wheel rim and big gauges that move with the tilting steering column to optimize viewing angle. 

Climate controls and stereo and navigation controls are densely arrayed in the center stack. They look cool, but you have to look at them to operate them. Adjusting a switch requires more attention than we prefer. 

The comfort zone is reserved for the front passenger, who gets the same range of seat adjustments as the driver, a separate adjustable center armrest and individual climate controls. 

The play zone, the back seat, has personal reading lamps, a center armrest with tray and storage, seatback pockets for storing DVDs and magazines, reclining seatbacks and chest-level air-conditioning vents. The optional DVD player ($1,750) has a seven-inch screen, a remote and two sets of wireless headphones. The play zone is surprisingly comfortable. Three adults fit comfortably in the split rear seats, and the recline feature makes it much more accommodating for taller folk than the rear-sloping roof might suggest. 

The FX has plenty of clever storage spots, including a lockable storage box in the center console with enough room for larger items like a purse. The door pockets flip out, and there are three hidden bins under the rear cargo floor. The rear seats fold flat easily with simple levers that are accessible from the side doors and the rear. The sculpted rear hatch pops with an electro-magnetic release. 

Total cargo capacity (64.5 cubic feet with the rear seat folded) is less than many square-shaped SUVs, but larger than in some others, including the BMW X5. Infiniti says it placed a higher priority on floor space than sheer volume, and the FX has a larger load floor than the X5 or Lexus RX330. Of course, that means its floor-to-ceiling measurement is shorter, as is the size of the opening under the sculpted hatch. At 30.6 inches, the load height is high. 

The optional 300-watt, 11-speaker Bose stereo was tuned for the middle-aged mid-life crisis male, and it seems to sound best blaring classic rock at high decibels. Infiniti says it worked with Bose specifically to emphasize bass and treble for rock and roll. 

To make life easier for those aging rockers, the FX can be operated without the key. With. 

Driving Impression

The Infiniti FX must be driven to be appreciated. It shares much of its chassis architecture with the rear-drive Nissan 350Z sports car and Infiniti G35 coupe. Rather than an SUV, we'd call it a fine luxury sport wagon with a higher seating position. It's more exciting to drive than a Volvo Cross Country, and bigger than an Audi allroad. 

Plant the V8-powered FX45's accelerator to the floor and you'll be rewarded with a healthy hot-rod roar. As revs rise, the sound becomes a higher-pitched hum. Brisk acceleration makes the big FX feel athletic and nimble. You get the feeling you can pass anything in front of you. And Infiniti's design objectives come more clearly into focus. 

The Infiniti FX45 offers comparable acceleration performance to the Porsche Cayenne S, according to each manufacturer's statistics. Infiniti says the FX45 can zip from 0 to 60 mph in slightly more than 6 seconds, while Porsche says the Cayenne S takes nearly 0.2 second longer. How can that be? Though Porsche's V8 engine is more powerful, the Infiniti FX is considerable lighter, so each of its 315 horses must haul fewer pounds. 

The V6-powered FX35 is no slouch, either. It launches impressively from a stop, largely because it has substantially more horsepower and torque than most other six-cylinder SUVs. There's as much oomph here as most owners will ever need. We found its acceleration performance entirely satisfactory. 

Granted, the step up to the V8 is noticeable, particularly when you stab the gas at, say, 60 mph. The FX45 will rocket to 80 at a much greater rate than the FX35. Yet the V8 also chugs fuel at a much greater rate, reducing range anywhere from 25 to 75 miles per tank, according to the EPA's numbers. Both FX models are electronically limited to a top speed of 130. 

All this power is managed with sophisticated electronics with names that sound like alphabet soup. The ATTESA E-TS (Advanced Total Traction Engineering System for All Electronic Torque Split) provides outstanding cornering capability due to its optimum 50/50 front/rear torque distribution, which can shift rearward up to 0/100 when conditions require. The system provides good starting traction and stable acceleration in snow-covered or off-road situations, since it always starts off with the torque split 50/50. 

The VDC electronic stability control system reduces engine output and/or lightly applies braking force to individual wheels when entering a corner too fast. It engages so gradually that we couldn't detect when it was working. 

The FX suspension reflects Infiniti's decision not to make this SUV an off-road vehicle. Off-road ability is enhanced by long travel and compliant suspension tuning, but those same characteristics compromises handling on smooth, winding roads. The FX is tuned for those winding roads. Despite its 7.6 inches of ground clearance, it has no skid plates or underside armor, and the up-down range of movement at its wheels is limited compared to most SUVs. 

In tight and sweeping corners alike, the body stays incredibly level, which is the plus side of its stiff suspension. We drove it hard, like we would a sports sedan. Understeer, or the sliding of the front tires that is the default skid condition in most vehicles, begins very gradually when you aim the FX into a corner, and the front wheels continue to push only slightly until you get near its very high cornering limits. When driven hard, the VDC allows a slight amount of power oversteer while cornering (a satisfying fish-tail effect in the rear), although we were never able to break the mammoth rear tires completely loose. As in the 350Z, the FX's steering is quick. It doesn't feel as telepathic as a Porsche's, but it doesn't feel light and loose like that in many SUVs, either. 

The brakes are good. The FX45 remains confident and stable under heavy braking, and that allowed us to drive it very quickly, without any scary momen. 

Summary

The Infiniti FX is the sports car of SUVs. It drives and rides like a sports sedan. It's no good for driving off road but works really well on winding mountain roads. It comes stuffed with the latest in active safety and passive safety. State of the art technology includes a rear-view camera, cruise control that senses traffic ahead, a key that can automatically unlocks the doors when you approach the car, plus an amazing stereo and a DVD video player for back-seat riders. If you're looking for a unique, road-burning, high-style luxury SUV, the Infiniti FX is one of a kind. 

New Car Test Drive editor Mitch McCullough is based in Southern California. 

Model Lineup

Infiniti FX35 RWD ($34,750); FX35 AWD ($36,250); FX45 AWD ($45,250). 

Assembled In

Kanagawa, Japan. 

Options As Tested

Touring Package ($2,900) includes leather seating surfaces, heated front seats, driver's memory seat, power lumbar support, power tilt/telescoping steering wheel, heated outside mirrors, power sunroof, 300-watt Bose audio system w 6-CD in-dash and 11 speakers, HomeLink universal transceiver, black roof rails, cargo cover and cargo net.