There was a time when the idea of a luxury SUV seemed as oxymoronic as gourmet instant coffee. Now it seems that every car manufacturer has this segment covered. When the first high-performance luxury SUVs debuted, they were met with the same sort of puzzled response. Some people might think this is just a passing fad, but like luxury SUVs before them, these oddly capable crossovers have been popping up with more and more frequency.

One of the more notable examples of this breed is the 2010 Infiniti FX50 crossover SUV. It's got the luxury part covered, with its carlike ride, sumptuous interior and wide range of features -- and it's got plenty of sport, too, thanks to prodigious V8 power and capable handling. It also boasts evocative styling and technological wizardry that would please nearly any early adopter. The FX50 may sound frivolous in theory, but it's a pretty impressive vehicle in the flesh.

What you'll notice first is the FX50's smooth and flowing lines, in stark contrast to the chunky, angular shapes of rival crossovers. The gaping grille may draw comparisons to various sea creatures, but overall we applaud Infiniti for daring to bring concept-car styling to the street. The FX50's athletic performance is similarly bold, starting with a powerful 5.0-liter V8 that cranks out a rumbling 390 horsepower and can rip off a 0-60-mph sprint in only 5.5 seconds. Winding roads are dispatched with equal aplomb -- the FX shares its basic underpinnings with the G37 sport sedan, and it shows.

The FX50 also provides plenty of high-tech power inside the cabin, including a nifty top-view camera and a standard navigation system upgraded for 2010 with DVD audio/video, Bluetooth streaming audio, a Zagat restaurant guide and weather reports. Additional technology is found in the safety department, where the FX50 offers an adaptive cruise control system and a lane-departure warning and prevention system.

There are some flaws in the FX50's formula, including a shortage of luggage space behind the rear seats, a sometimes unyielding suspension and the V8's lack of refinement at high engine speeds. Yet one of the FX's main competitors, the BMW X6, suffers from similar space constraints, and another notable rival, the Porsche Cayenne S, lacks the FX's head-turning style. It really comes down to whether the 2010 Infiniti FX50's striking curves, formidable performance and boatloads of technology combine to make it your cup o' joe.

The 2010 Infiniti FX50 is a five-passenger midsize luxury crossover SUV that is offered in one well-appointed trim level. Standard features include 21-inch alloy wheels, automatic bi-xenon headlights, foglights, heated outside mirrors, a power liftgate, a sunroof, keyless entry and ignition, a power tilt-and-telescoping steering wheel with audio controls, heated and ventilated power front seats with driver memory settings, full power accessories, quilted leather upholstery, dual-zone automatic climate control with a filtration system, a tonneau cover and aluminum pedals.

On the technology front, the FX50 comes standard with a top-view multicamera parking system and a hard-drive-based navigation system with voice recognition, real-time traffic, weather reports and a Zagat restaurant guide. Also included is an 11-speaker Bose audio system with a DVD/CD/MP3 player, satellite radio, Bluetooth, a 9.3GB music server and iPod integration.

An optional Sport package adds tinted headlights, side air vents, lower side trim, active rear steering, adaptive two-mode suspension dampers, paddle shifters and sport front seats. The Technology package includes adaptive front headlights, a lane-departure warning and prevention system, adaptive cruise control, intelligent brake assist and rain-sensing front wipers. A rear-seat entertainment system and an exterior styling kit are also available.

The 2010 Infiniti FX50 is powered by a 5.0-liter V8 that produces 390 hp and 369 pound-feet of torque. Power is sent to all four wheels through a seven-speed automatic transmission with manual shift control. Acceleration is quick, with the 0-60-mph sprint taking just 5.5 seconds. The EPA estimates fuel economy at 14 mpg city/20 mpg highway and 16 mpg in combined driving.

Antilock disc brakes with brake assist, front-seat-mounted side airbags, full-length side curtain airbags, traction control and stability control are all standard on the 2010 Infiniti FX50. A lane-departure warning and prevention system is optional, as are adaptive cruise control and intelligent brake assist. The latter uses the laser range finder from the adaptive cruise control to analyze closing speeds to an obstacle ahead; if a forward collision is imminent, the system sounds a warning to prompt driver action and can automatically apply the brakes up to 0.5g.

In crash tests, the Insurance Institute for Highway Safety awarded the FX50 its highest score of "Good" for frontal-offset impact protection.

The 2010 Infiniti FX50's V8 is smooth and refined in most situations, though it reveals some coarseness and vibration near redline that's absent from rivals like the X6 and Cayenne. Refinement issues aside, there's substantial power on tap -- the FX50 hurtles forward effortlessly when you give it the spurs.

On serpentine back roads, the FX50 handles more like a sport wagon than a crossover SUV. The steering has a tight, direct feel, while the suspension handles the curves with ease. The brakes also have a sporty feel and deliver consistent stopping distances, even after repeated hard stops. The FX also works well as a highway cruiser, though the road noise from the large 21-inch tires can become intrusive. Also, impact harshness is sometimes pronounced on pockmarked surfaces.

Read our Infiniti FX50 Long-Term 20,000-Mile Test

The 2010 Infiniti FX50 features a rich and luxurious interior with plentiful soft-touch materials and supple leather. The vehicle's audio and navigation system interface is one of the best in the business; it's a bit tricky to figure out at first, but the various control redundancies make it easy to find a way of operation that suits your style. The standard 360-degree camera system provides a highly useful top-down view of the FX's proximity to other cars or curbs while parking.

The front seats provide ample adjustment as well as head- and legroom; most people will find them quite comfortable and supportive, though the optional sport seats may seem confining to those with wider derrieres. The rear seats aren't quite as enjoyable, as long-legged passengers will find the accommodations a bit cramped relative to those in some competing vehicles. Luggage space behind the rear seats is 25 cubic feet, and folding the rear seatbacks opens up 62 cubes -- both below-average figures for a midsize crossover.