The 2010 Ford Fusion is a car that blurs the boundaries between a midcycle refresh and a ground-up redesign. Its platform is shared with last year's Fusion, which means it's still fundamentally a stretched version of the first-generation Mazda 6. Yet practically everything else is new -- exterior design, interior design, powertrains, you name it. Before you write off the 2010 Fusion as a warmed-over version of the previous model, we suggest you take one for a test-drive. The old Fusion was already a pretty good midsize sedan, and thanks to Ford's determination to rectify its flaws, the new one's even better.

If you don't believe us, take a look at our criticisms of last year's Fusion. For example, we griped that its engines were short on power. Well, the 2010 Fusion offers a competitive 175-horsepower four-cylinder base engine, a juiced-up 240-hp version of the familiar 3.0-liter V6 and a 3.5-liter V6 good for 263 hp in the Fusion Sport. Fuel efficiency also wasn't up to snuff on last year's model, but this time around the Fusion boasts class-leading fuel economy in four-cylinder guise. You had to pay extra for stability control on the old Fusion, but guess what -- it's standard on the new one. Indeed, Ford did such a good job of addressing our complaints that we're having a hard time finding fault with its mostly new midsizer.

Other changes for 2010 include refreshed exterior and interior styling. We're particularly pleased with the interior makeover. Whereas the previous Fusion's cabin felt distinctly dated, the new one compares favorably with rival layouts, featuring an attractive design and improved ergonomics. The 2010 Fusion's two clearest shortcomings will likely be lamented only by driving enthusiasts -- the standard 2.5-liter four-cylinder emits a rather unpleasant racket under hard acceleration, and the new electric power-assist steering system (standard on all but the Fusion Sport) lacks the commendable communicativeness of the previous model's hydraulic setup. Of course, many four-cylinder family sedans are guilty of the same offenses, and that hasn't stopped them from racking up accolades and impressive sales numbers.

The market is overflowing with competent family sedans, but the Fusion's well-rounded nature helps set it apart. Apart from its Mercury Milan sibling, no competitor offers the excellent Sync multimedia integration system, and few boast available all-wheel drive. Only the Nissan Altima handles markedly better, and the Fusion's ride is more compliant. For spirited drivers, the Fusion Sport's upgraded engine and sport-tuned suspension should satisfy. Don't let the 2010 Ford Fusion's familiar underpinnings deter you -- if you're on the market for a midsize sedan, this one belongs on your short list.

The 2010 Ford Fusion is a midsize sedan available in S, SE, Sport and SEL trim levels. The base S comes standard with 16-inch alloy wheels, keyless entry, full power accessories, a trip computer, cruise control, air-conditioning, 60/40-split rear seats, a tilt-telescoping steering wheel and a four-speaker stereo with a CD player and an auxiliary audio jack. The SE adds 17-inch steel wheels (alloy-look covers), foglamps, dual exhaust tips, a fold-flat passenger seat, a six-way power driver seat with manual recline and lumbar, steering wheel radio controls and a six-speaker stereo with satellite radio.

The Sport tacks on a sport-tuned suspension and steering setup, 18-inch alloy wheels, exclusive styling cues inside and out, an auto-dimming rearview mirror, a leather-wrapped steering wheel and shift knob, an eight-way power driver seat, unique leather-trimmed seats and the Sync entertainment and communications interface. The Fusion SEL steps up to automatic headlights, heated exterior mirrors, puddle lights, a numerical keyless entry pad, ambient lighting, dual-zone automatic climate control, heated power-adjustable front seats and leather upholstery.

Options on the base S are limited to remote engine start (automatic transmission only) and all-weather floor mats, which are available across the lineup. SE options include an auto-dimming rearview mirror, Sync and a sunroof. The Sport model can be optioned with the SEL's standard equipment plus a blind-spot warning system, a back-up camera, a sunroof and a 12-speaker Sony sound system with a six-CD changer. Among SEL options are 18-inch wheels and a rear deck spoiler. Optional on Sport and SEL models is a voice-activated hard-drive-based navigation system with Travel Link (includes real-time traffic and weather information). Note that adding the navigation system downgrades the CD changer to a single-disc unit if the Sony sound system is also specified. Reverse parking sensors are a stand-alone option on all models except the S.

The 2010 Ford Fusion features three different engines. The base power plant -- standard on S, SE and SEL models -- is a 2.5-liter four-cylinder engine that produces 175 hp and 172 pound-feet of torque. This mill comes with a six-speed manual transmission by default, while a six-speed automatic is optional. A 3.0-liter V6 putting out 240 hp and 223 lb-ft of torque is optional on SE and SEL models, and it's only available with a six-speed automatic. The Sport model comes with a more powerful 3.5-liter V6 that generates 263 hp and 249 lb-ft of torque. Front-wheel drive is standard on four-cylinder and Sport models, while all-wheel drive is optional on the Sport and mandatory on the V6-powered SEL.

Fuel economy ratings for the four-cylinder Fusion with the automatic transmission are an impressive 23 mpg city and 34 mpg highway.

Antilock disc brakes, stability control, front-seat side airbags and side curtain airbags are standard on all Fusions. In government crash tests, the Fusion achieved a perfect five stars for frontal protection and front side protection. It got four stars for rear side protection. The Insurance Institute for Highway Safety gave the Fusion its highest rating of "Good" in its frontal-offset, side and roof strength tests.

In Edmunds brake testing, the Fusion SEL came to a stop from 60 mph in a longer-than-average 130 feet. The Fusion Sport did it in a much better 123 feet.

The 2010 Ford Fusion is one of the most engaging family sedans from the driver's perspective. Body control through corners is impressive, yet the ride remains comfortable and hushed. The Sport model feels particularly buttoned-down thanks to its sport-tuned suspension. Performance from the base four-cylinder is adequate, and while the revised 3.0-liter V6 is still down on power compared to its rivals, it's plenty capable for most shoppers in this segment. Should you find the 3.0-liter unit lacking, the 3.5-liter V6 is a good match for competing V6s. On the downside, the electric power steering on non-Sport models is light and numb, and the four-cylinder engine makes raucous noises during spirited acceleration.

The 2010 Ford Fusion's cabin will be familiar to anyone who has spent time in the previous Fusion, but that's not a bad thing. Soft-touch materials abound, and the overall look is austere but attractive. The center stack is a bit button-happy, but it's a significant ergonomic and aesthetic improvement over its dated predecessor. The available Sync system works great, integrating audio and Bluetooth functionality with voice-recognition technology to provide easy hands-free operation of cell phones and portable MP3 players.

There's plenty of room for passengers in the Fusion. While Ford's midsizer isn't the largest car in its class, its generous interior dimensions prove that such sedans need not be as controversially large as the Accord or Mazda 6 in order to accommodate families' needs. A pair of adults will be content in back (especially given the new model's rear seat headrests) and storage space is adequate. The 16.5-cubic-foot trunk is one of the largest around, and the split-folding rear seat enables larger items to be carried inside the car.