Porsche Cayenne. BMW X5. Mercedes ML55 AMG: These aren't names competitors usually toss around lightly. But Infiniti, which is the latest luxury marque to attempt a U.S. turnaround through a recreated identity, is confident its new FX45 cross/utility vehicle easily will slide into that elite grouping.

Officials at Nissan Motor Co. Ltd.'s luxury division beg for comparisons between their luxury CUV and the Porsches and BMWs of the world — much the same way Infiniti last year threw down the gauntlet directly in front of the BMW 3-Series with its outstanding G35 sedan and coupe.

Infiniti, which in its 13-year U.S. history has been considered the least relevant of the Japanese luxury brands, finally is getting attention from headquarters in Japan and desperately wants to be taken seriously.

Key to that is the establishment of an image completely separate from Nissan's. Yes, the family resemblance between Nissan's new Murano CUV and Infiniti's equally handsome FX is hard to miss. But Infiniti says the most crucial differentiators are under the skin: Nissans are earmarked primarily as front-engine/front-drive vehicles, while Infiniti cars, including the FX, will be front-engine, rear-drive.

The projected Infiniti image, then, is that of “purist” performance and the FX — which Infiniti calls half SUV, half sports car — must be able to stack up with the Germans, who invented purist performance.

On paper, it's a good battle: The FX45 is powered by the VK 4.5L DOHC V-8, which makes 315 hp and 329 lb.-ft. (446 Nm) of torque, healthy figures that beat the already aging BMW X5 (290 hp, 324 lb.-ft. [439 Nm]).

The Porsche Cayenne S, new for '03, puts up an unbeatable 340 hp (with its naturally aspirated 4.5L DOHC V-8), but its torque falls short at 310 lb.-ft. (420 Nm). And, Infiniti reminds, the FX has a knockout weight advantage: It's an astonishing 650 lbs. (294 kg) lighter than the Cayenne and 525 lbs. (238 kg) lighter than the X5. Infiniti claims that its 0-60 mph (97 km/h) time of 6.3 seconds bests both Germans.

And then there's the small matter of money: The FX45 loaded with every option costs less than the least-expensive Cayenne.

But that's just a fragment of the story. To understand the full competitive force of the FX, one must consider the other trim level: FX35.

Infiniti has downplayed the V-6-powered FX35, but it is projected to comprise 70% of the 30,000 FXs expected to sell annually.

The FX35 will prove the better choice. It's powered by Nissan's always excellent VQ 3.5L V-6, tuned to make 280 hp and 270 lb.-ft. (366 Nm) of torque.

The way we see it, a nominal 35 hp, a few tweaks to the 4-wheel independent suspension and 20-in. wheels rather than 18-inchers is the tacit difference between the two FXs. That's hardly enough to justify the price spread: $44,200 for the base FX45 versus $35,700 for the FX35.

Or again go with the BMW comparison: The FX35 hammers the 3L I-6 in the X5 3.0 by an embarrassing 55 hp, not to mention heartily out-torquing the BMW by 56 lb.-ft. (76 Nm). Oh, and the FX35 weighs 329 lbs. (149 kg) less.

The FX combines elements from the diametrically opposed SUV and sports-car segments. The all-wheel-drive system, standard with both engines, borrows from Nissan's Skyline GTR super car: Its central component is an electromagnetic clutch-pack center differential that varies the tractive force sent to front or rear axles.

At initial acceleration, a small amount of weight transfer maintains a 50:50 power distribution between front and rear axles. At cruise, the system biases to the rear but is able to send up to 50% of torque to the front if the rear wheels spin.

Though not permanent AWD, Infiniti says it handles better than BMW's X5, with a center differential that maintains a fixed 62:38 rear/front torque split at all times.

The 5-speed automatic has a manual shift mode that holds gears until the driver chooses to shift. Vehicle Dynamic Control with Traction Control is standard for FX.

Infiniti says exterior dimensions equal that of Cayenne and are larger than the X5 and Lexus RX 300.

The utility area of 27.4 cu.-ft. (0.8 cu.-m) doesn't stack up to competitors because of the steep rake of the roofline — what Infiniti calls the “taut canopy” design. Usable space and floor space, officials counter, equal the competition and — more important than the plywood test — can accommodate four sets of golf clubs.

Interior materials are supple and high-grade, and the vehicle offers all the accoutrements of a luxury SUV.

SPECIFICATIONS

2003 Infiniti FX45
Vehicle type: Front-engine, all-wheel drive, 5-passenger 4-door cross/utility vehicle
Engine: 4.5L (4,494 cc) DOHC V-8 aluminum block/aluminum heads
Power (SAE net): 315 hp @ 6,400 rpm
Torque: 329 lb.-ft. (446 Nm) @ 4,000 rpm
Compression ratio: 10.5:1
Bore × Stroke (mm): 93 × 82.7
Transmission: 5-speed automatic
Wheelbase: 112.2 ins. (285 cm)
Overall length: 189.1 ins. (480 cm)
Overall width: 75.8 ins. (193 cm)
Overall height: 65 ins. (165 cm)
Curb weight: 4,299 lbs. (1,951 kg)
Market competition: BMW X5; Lexus RX 330; Mercedes ML500; Porsche Cayenne S