Although the Mazda 6 has not sold in quite the numbers the company had hoped, positive word of mouth has gradually spread among midsize car buyers. And for good reason: The 6 is a unique vehicle, combining the comfort and room that commuters and families require, with a level of style and handling dynamics rarely found in this class. Sensing a golden opportunity, Mazda has expanded its lineup to include a high-performance version of the 6. Dubbed the Mazdaspeed 6, this sport sedan finds Mazda scaling bold new heights in handling and performance.

The Mazdaspeed 6 gets its juice from a turbocharged, direct-injected 2.3-liter inline four-cylinder engine, which provides an impressive 274 horsepower and 280 pound-feet of torque. Turbo lag is usually an issue when manufacturers wring this much power from a relatively small engine, but the engine's direct-injection technology mostly eliminates this problem. However, power drops off early at the top end, about 1,000 rpm short of the Mazdaspeed 6's seven grand redline. The turbo four is mated to a six-speed manual transmission that routes power through Mazda's new Active Torque-Split All-Wheel-Drive system. The computer-controlled system varies the power split between 100 percent going to the front wheels to a 50/50 front/rear ratio, taking into account steering angle, yaw rate and lateral Gs. It can also choose from Normal, Sports and Snow modes to optimize traction for the road conditions. A limited-slip rear differential borrowed from the Mazda RX-8 is also part of the package. To further enhance handling, the Mazdaspeed 6's chassis is 50-percent more torsionally rigid than the standard 6's. Additionally, suspension settings are stiffer, the brakes are larger, and stability control is standard.

Mazda's latest sedan wears its high-performance ambitions on its sleeve, but it does so discreetly. Compared to the standard 6 it has a domed hood to accommodate the turbocharger and a five-point upper grille section that serves as the air intake, but there's no big hood scoop. Flared side skirts flank unique 18-inch aluminum wheels. In back, you'll find enlarged exhaust outlets and a rear lip spoiler. Inside the cabin, you'll find sport bucket front seats, stainless steel scuff plates and aluminum pedals.

The Mazda 6 is already one of the best handling midsize sedans on the market, so it's no surprise that the Mazdaspeed version delivers enough excitement to keep an enthusiast grinning from ear to ear on back roads, while offering enough room for his kids in the backseat. It should also be of particular interest to buyers put off by the boy-racer styling and more hard-core attitude found on the Mitsubishi Lancer Evolution and Subaru WRX STI.

The Mazdaspeed 6 is available as a sedan only in Sport and Grand Touring trim levels. Standard features on Sport models include a 18-inch alloy wheels, HID headlights, sport seats, automatic climate control, a 200-watt Bose audio system with an in-dash six-disc CD changer, a tilt-and-telescoping steering wheel with satellite audio controls, one-touch power windows and cruise control. Step up to the Grand Touring trim and you get leather upholstery, an eight-way power driver seat, heated front seats and a keyless startup system. Significant options include a DVD-based navigation system and, for the Grand Touring trim, a moonroof.

The Mazdaspeed 6 is powered by a turbocharged, 2.3-liter inline four-cylinder with direct injection. The engine produces 274 hp and 280 lb-ft of torque, and is mated to a six-speed manual transmission. An automatic transmission is not available. A computer-controlled all-wheel-drive system is standard, and it's capable of delivering up to 50 percent of engine torque to the rear wheels to improve handling and grip. Zero to 60 mph takes 6.1 seconds in the Mazdaspeed 6, and the quarter-mile passes by in 14.3 seconds.

Four-wheel antilock disc brakes with Electronic Brakeforce Distribution are standard; the rotors measure 12.6 inches in front, 12.4 inches in back. Stability control is also standard as are front-seat side airbags, full-length head curtain airbags and whiplash-reducing front seats. In government crash tests, the standard 6 received a perfect five stars for frontal-impact protection. In side-impact tests, the 6 earned just three stars for front-occupant protection and four stars for rear passengers, but the vehicle tested did not have side airbags. In IIHS frontal-offset crash testing, the Mazda earned the top rating of "Good." In IIHS side-impact testing, it rated "Poor," but again the vehicle tested did not have side airbags.

The standard Mazda 6 has always been light on torque, but the Mazdaspeed version's direct-injection turbocharged engine puts that concern to rest. There's a slight amount of turbo lag off the line, but acceleration is quite strong thereafter with a midrange that borders on explosive. Until you acclimate, you might find the short-stroke clutch's engagement abrupt, so you'll want to check this out during your test-drive. Handling has always been a strength for the 6, and the Mazdaspeed 6 sedan only increases those thresholds. Its tightened suspension allows very little body roll around corners and its precise steering offers plenty of feedback. Add in a sticky set of 18-inch tires and an all-wheel-drive system to spread the power around and there's no shortage of thrills on twisty back roads.

The Mazdaspeed 6's performance mission is reflected in its sport bucket front seats, stainless steel scuff plates and gleaming alloy pedal set. Easy-to-operate controls keep things simple for the driver. Although tall adults may find the backseat a little tight compared to the accommodations in competitors like the Chrysler 300C and Nissan Altima SE-R, there's plenty of room for children. Note that the addition of AWD mechanicals drops the 6's trunk capacity to 12.4 cubic feet and eliminates the rear seat's split-folding capability.