2005 Infiniti FX Blending Performance, Utility, and Style
by Keith Burton

In what is clearly among the most sporting of crossover SUVs, the Infiniti FX enters the 2005 year with new state-of-the-art safety enhancements – including the revolutionary Lane Departure Warning (LDW) system that helps alert drivers to an unintended movement of the vehicle out of a designated traffic lane. The LDW system, which utilizes a small camera, speed sensor, an indicator and an audible warning buzzer, is offered on all 2005 FX45 and FX35 models. It is the first production car application of LDW in North America.

In addition to LDW, all 2005 Infiniti FXs are now equipped with standard roof-mounted curtain supplemental curtain air bags with rollover protection for front and rear outboard seat occupants.

Other enhancements to the FX lineup include the addition of dark chrome grille, headlight and taillight accents to the FX45 (also available as part of the V6 Sport Package on FX35 models), a new key fob design for the Infiniti Intelligent Key system and two new exterior colors, Sapphire and Sheer Platinum. Interior changes include a new standard etched aluminum trim.

Again for the 2005 model year the FX is available in two designations, each offering the practical utility of a SUV with the heart of a sports car. The FX45 is offered with a standard 4.5-liter V8 engine and all-wheel drive, while the FX35 comes with a standard 3.5-liter V6 and all-wheel or rear-wheel drive.

Bold and Sleek Styling

In creating the FX, its designers sought what they called a "cool fusion" – the blending of a substantial, SUV lower body with the sleek, elegant upper body more reminiscent of a classic sports car or sports GT. We think the look is just right for this vehicle and it often drew admiring stares from other drivers around the Mississippi Coast.

The FX exterior features a wide, aggressive stance with a long, sleek hood, sleek roof and a "taut canopy" greenhouse. The short front and rear overhangs provide SUV-level approach and departure angles, while also helping accentuate the long wheelbase, wide track and large tires (18-inch on FX35, 20-inch on FX45). The wide yet narrow headlights and taillights give the FX an "in-motion" look, with the taillights extending past the body slightly to help create aerodynamic downforce. The exterior design also includes a large Infiniti signature grille, standard fog lights, xenon headlights and large, split dual tailpipes with chrome finishers.

All FX models utilize a modified version of the advanced FM (Front Mid-ship) platform, which positions the engine behind the front axle. This results in an optimized front-to-rear weight balance of 52:48 (V6 RWD), which factors in weight transfer during key handling maneuvers, such as entering and exiting corners. We can tell you that its handling is first rate, especially for a vehicle this size. The steering is spot-on and is quick, which allows this vehicle to literally zing around turns and curves.

The FX's long 112.2-inch wheelbase and wide track (62.7-inches front, 64.6-inches rear) combine with large wheels and tires (standard 20-inch on FX45) to provide a stable foundation for on- or off-road driving – as well as a large interior for both passengers and cargo. But the suspension is a bit stiff, which while great for handling, may turn some people off. It would have been great if Infiniti's engineers had used adjustable shocks with a soft setting. I know, I know, zippy handling is great fun, but so is comfort over the rough stuff.

A Choice of Engines

Two engines are available  2005, starting with the 4.5-liter DOHC V8. This advanced powerplant, also used in the Infiniti Q45 sedan, has been specially tuned for use in the FX45 to produce 315 horsepower and 329 lb-ft of torque.

The engine's advanced design includes titanium valves, modular cylinder heads, microfinished crankshaft, lightweight pistons, super-silent single stage cam drive chain and a hydraulically driven cooling fan to help optimize performance.

In addition, the VK45DE is outfitted with a variable length air induction system and Continuously Variable Valve Timing Control System (CVTCS) to enhance the engine’s power delivery and operation efficiency.

Also offered is a 3.5-liter DOHC 24-valve V6 engine with aluminum-alloy block and heads and electronically controlled “drive-by-wire” throttle system. Both the all-wheel drive and rear-wheel drive V6 engine-equipped versions are designated as FX35 models.

The V6 has been tuned specifically for use in the FX35, with a horsepower rating of 280. Torque is rated at 270 lb-ft. A 5-speed automatic transmission with manual shift mode, designed for high torque capacity and light weight, is standard with both V8- and V6-equipped models. A special Snow-Mode function changes the throttle input algorithm in low-speed slippery road conditions (once activated by the driver) for enhanced traction control.

Our tester was the V8, and it definitely is the engine to get for the most zoom. The V8 makes this a truly swift interstate cruiser with effortless acceleration and power for high speed driving.

Infiniti’s advanced Vehicle Dynamic Control (VDC) system with Traction Control System is also standard on every 2005 FX. Vehicle Dynamic Control adjusts brake pressure and engine torque automatically in understeer, oversteer or slippery road surface situations, helping the drivers keep their intended paths. In the heavy rains and flood-soaked roads on the Coast, the FX had absolutely no trouble. The feeling was one of security and confidence.

A big reason for the FX's sure-footedness is its massive 20-inch wheels and all-wheel drive system. The AWD system uses an advanced torque split control strategy that automatically transfers optimum torque to the wheels according to road and driving conditions. It provides terrific cornering capability due to optimum torque distribution for front and rear (50:50 up to 0:100). The system also provides high starting traction performance and smooth, stable acceleration, especially in low traction situations with the 50:50 torque split at standing start.

The FX's dynamic handling is a result of its advanced 4-wheel independent suspension, which makes extensive use of aluminum-alloy components to reduce unsprung weight. The front suspension utilizes an independent front strut design, while the rear features a multi-link design. Large diameter stabilizer bars are utilized front and rear (front only on FX35 RWD model).

Standard braking system components include 4-wheel ventilated disc brakes, Brake Assist  and Electronic Brake force Distribution. Responsive steering is provided by an engine-speed-sensitive power rack-and-pinion steering system.

Also available on FX45 models with the Intelligent Cruise Control System is a special feature of the standard Brake Assist system – Preview Braking. Brake Assist with preview function is designed to help improve brake response. Whereas normally braking is activated only when the driver recognizes the need and moves his or her foot to activate the brake pedal, the preview function utilizes the ICC sensors to identify sudden braking situations (by sensing the vehicle ahead in the same lane and the distance and relative speed from it) and “pre-pressurizes” the Brake Assist system before the driver steps on the brake pedal. This helps maximize braking response and performance by reducing the normal brake system activation time lag.

High Tech Interior with Luxurious Comfort

The five-passenger interior of the FX blends the comfort and amenities of a luxury car with an array of high tech driver and passenger features. In front are driver-oriented controls, available 10-way power-adjustable seat with memory function, driver-dedicated automatic air conditioning, information display monitor (6.3-inch standard, 7.0-inch with the Technology Package) and a three-spoke, leather-wrapped steering wheel with tilt (moves in tandem with the instrument cluster) and telescope (power-operated on FX45), integrated cruise and available steering wheel-mounted audio system controls.

While neat looking and comfortable, our tester had an interior that was a bit stark, all black and brushed silver. It is a sporty look, but in such a pricey vehicle, we would expect a touch of softness somewhere, like perhaps a bit of real wood trim.

The front passenger is treated to an available 8-way power-adjustable seat, passenger adjustable armrest and individual air conditioning control. Available rear seat passenger features include personal reading lamps, center armrest with tray and storage, dual seatback pockets for storing DVDs and magazines, reclining seats and rear B-pillar mounted air conditioning vents for enhanced cooling performance.

Every FX model also offers exceptional utility, including a large cargo area with easy cargo accessibility, flip-down rear seats with quick-release levers conveniently located in the cargo area, three underfloor storage compartments and a lightweight, steel-reinforced composite rear cargo door with electromagnetic opener switch.

A number of special high tech features are also available, including an advanced DVD-based Infiniti Navigation System, Intelligent Key with keyless entry and engine start system and RearView Monitor.

The Intelligent Key is a new generation keyless system that eliminates the need to use the key fob when locking, unlocking and starting the engine. The key fob, which incorporates a circuit board, emergency key and transponder, can be carried with the driver in a pocket, briefcase or purse. To unlock or lock the door, you push a little black button on the outside door handle. The transponder checks the Intelligent Key unit for the correct identification and unlocks or locks the doors.

To start the engine, the driver pushes the ignition knob into the steering column. If the identification is correct, the knob can be turned to start the engine. The knob is rotated back to the ACC position to stop the engine. The engine can also be started conventionally by inserting the emergency key into the ignition slot.

The Intelligent Key has the same functions as current remote entry systems, including panic alarm and selective unlock mode and answer back.

Another cool feature on the FX is the RearView Monitor, which projects a view of what's behind the FX onto the navigation system monitor using a small camera mounted near the rear license plate (the system operates only when reverse gear is selected). There is also a neat Intelligent Cruise Control System, which uses the brakes, throttle and laser sensors, to maintain a set distance between the FX and a vehicle in front of it.

The Infiniti Mobile Entertainment System features a DVD player with 6.3-inch roof-mounted rear LCD screen. A 6-CD audio system with six speakers is standard, while a 300-watt digital Bose premium audio system with 11 speakers is also available.

Overall, this is one fun-to-drive SUV where the enjoyment is on the the road instead of  some back-wood sandlot. Our FX was in the luxury class as far as price, at around $54,000. But for that you have all the amenities and terrific on-road performance that is on par with sport sedans.

 Specifications