Adapt or die. This Darwinian adage applies to birds, business and, well, family SUVs. And so the 2013 Nissan Pathfinder adapts to the needs of consumers by breaking away from its trucklike, off-road-ready roots to become a more comfortable, car-based, family-ready crossover SUV.

The previous Pathfinder was a heavy, rugged truck adept at off-road adventures and towing. But its downsides included cramped quarters for second- and third-row passengers, a trucklike driving demeanor and mediocre fuel mileage. Nissan figured that on a daily basis most folks would prefer a comfortable cabin and good fuel economy to infrequently used extreme capabilities.

That's why the redesigned 2013 Pathfinder is built on a unibody structure shared with the equally new Infiniti JX crossover. It adopts a 260-horsepower 3.5-liter V6 matched to a continuously variable transmission (CVT). The vehicle is 500 pounds lighter than the one it replaces, one factor in fuel economy estimates of 20 mpg city/26 mpg highway and 22 combined, which make the Pathfinder one of the most fuel-efficient vehicles in a class that includes the Ford Explorer and Honda Pilot.

Yes, the lighter and more efficient new Pathfinder gives up some towing capacity to its forebear, but it can still tow up to 5,000 pounds. That's a strong number for a midsize, seven-passenger crossover whose duties probably won't stray far from pulling a pair of jet skis to the lake or carting the kids to sports and dance practices. Like the Infiniti JX, the Pathfinder offers a sliding second-row seat that can tilt and fold forward even with a child seat in place, making access to the adult-friendly third row much easier.

The 2013 Nissan Pathfinder has a lot going for it, namely smooth performance, impressive fuel economy numbers and a welcoming cabin. But even if it's now better suited to compete in the popular seven-passenger SUV segment, the Pathfinder still faces some tough competition. Our top picks in the segment remain the Chevrolet Traverse, Ford Flex and Mazda CX-9, each of which is roomier than the Nissan. However, against the strong-selling Ford Explorer, Honda Pilot and Toyota Highlander, the Pathfinder has definitely adapted to become a very appealing alternative.

The 2013 Nissan Pathfinder is a midsize seven-passenger SUV offered in four trim levels: S, SV, SL and Platinum.

Standard equipment on the S includes 18-inch alloy wheels, rear privacy glass, keyless entry, tri-zone automatic climate control, cruise control, a height-adjustable driver seat, a 60/40-split second-row seat (slides, reclines and folds), a tilt-and-telescoping steering wheel and a six-speaker sound system with a six-CD changer.

The SV adds automatic headlights, keyless ignition/entry, an eight-way power driver seat, a leather-wrapped steering wheel, Bluetooth phone connectivity, a 7-inch color multi-information display, a rearview camera and an upgraded audio system with a single-CD player, satellite radio and a USB/iPod interface.

Step up to the SL trim level and you get foglights, roof rack rails, a power liftgate, rear parking sensors, heated mirrors, leather upholstery, heated front and rear seats, driver memory functions, a four-way power passenger seat, an auto-dimming rearview mirror and a compass.

The Platinum trim adds 20-inch wheels, a towing package, a multiview parking camera, a power-adjustable heated steering wheel, cooled front seats, a 120-volt power outlet, a navigation system, real-time traffic and other information, and a 13-speaker Bose audio system with Bluetooth audio connectivity and a DVD player.

Optional equipment is grouped into three packages. The SL Premium package includes the Bose audio system, the 120-volt power outlet, a large dual panoramic sunroof and the towing package. The Platinum Premium package includes the dual panoramic sunroof and a DVD entertainment system with dual displays.

The 2013 Nissan Pathfinder is powered by a 3.5-liter V6 good for 260 hp and 240 pound-feet of torque. A CVT and front-wheel drive are standard. An optional all-wheel-drive system automatically apportions power between the front and rear axles as needed or allows the driver to lock in a 50/50 ratio.

In Edmunds performance testing, a four-wheel-drive Pathfinder went from zero to 60 mph in 8.0 seconds, which is a little better than average. EPA fuel economy estimates are 20 mpg city/26 mpg highway and 22 mpg combined with front-wheel drive and 19/25/21 with 4WD. Properly equipped, the Pathfinder can tow 5,000 pounds.

Standard safety features include antilock disc brakes, stability and traction control, front-seat side airbags and full-length side curtain airbags. In Edmunds brake testing, the 2013 Nissan Pathfinder came to a stop from 60 mph in 124 feet, a little better than average for this segment.

Although Nissan likely makes the best CVT in the business, acceleration off the mark is a bit sluggish, though it pulls nicely once underway (hence the competitive 0-60 time). Overall performance is smooth and more than adequate, especially in light of the promising fuel economy figures. Although the brake pedal feels a bit spongy, the brakes themselves are strong enough, with shorter than average stopping ability.

The priority of the chassis engineers was clearly achieving a comfortable, quiet ride over broken pavement and when cruising on the highway. The 2013 Nissan Pathfinder's handling, however, is rather tepid, with lazy turn-in response and noticeable body roll when pushed. If you want to feel more connected to the road, we suggest opting for the Mazda CX-9 or Nissan's five-passenger Murano.

The Pathfinder's cabin is put together well and boasts quality materials. Indeed, you may think you're in an Infiniti once you get inside the Platinum trim level, given the variety of rich finishes and accents. Despite the abundance of features (especially in higher trims), the various controls are easy to reach and intuitive.

Seat comfort up front is very good. Same goes for the second row, which slides and reclines to optimize comfort for passengers or cargo space behind as needs dictate. Access to the third row is eased by the second row's tilt and slide feature, which can be used even when a child seat is in place. The third row offers enough headroom for 6-foot passengers, but clearance gets a little tight beyond that.

Maximum cargo space stands at 79.8 cubic feet -- about the same as an Explorer and Pilot, though significantly less than what's available from some larger three-row crossovers like the GMC Acadia.