Mazda North American Operations has had a string of good luck since it launched its Mazda6 midsize car three years ago, eventually available in sedan, wagon and hatchback body styles.

The Japanese auto maker now unleashes the Mazdaspeed6, bridging its best-selling midsize car with its Mazdaspeed performance brand. Mazda has modest expectations for the Mazdaspeed6, which comes only in the sedan body style. Just 5,000 annual sales in the U.S. are expected.

The Mazdaspeed6 is a good car that deserves to sell in greater numbers. The car's likely competition is other racing-inspired offerings, such as the Subaru WRX STi and Mitsubishi Evolution.

But these cars lack the basic refinement and creature comforts found in the Mazdaspeed6, which appears to be in a segment unto itself.

The car fulfills Mazda's promise to introduce all-wheel drive to the Mazda6 architecture, which required significant packaging changes. Mazda is not able to equip the standard 4-cyl. Mazda6 with AWD due to lack of horsepower, and the unique instrument panel in V-6 Mazda6 models prevents an AWD application.

The system in the Mazdaspeed6 is an active torque split design, with a center differential that distributes power to the front and rear axles in a front/rear range from a 100/0 to 50/50. The driver feels the rear wheels accepting drive torque when entering a sharp turn at high speeds.

Mazda has beefed up the existing Mazda6 chassis — double wishbones up front and advanced multilink setup in the vehicle's rear — to support the AWD system, using new crossmembers that add stiffness and hefty anti-roll bars for steadiness.

The other noteworthy hardware upgrade for the Mazdaspeed6 is its turbocharged 2.3L DOHC I-4 featuring direct-injection gasoline (DIG) technology.

The DIG system and turbocharging hikes the power of this engine (a global architecture used extensively by Mazda and parent Ford Motor Co.) from the 160 hp and 155 lb.-ft. (210 Nm) of torque it makes in normally aspirated, port-injected configuration to a whopping 274 hp and 280 lb.-ft. (380 Nm) of torque. The one and only transmission is a 6-speed manual.

Mazda's Direct Injection Spark Ignition system (DISI), one of the first to combine DIG with turbocharging, primarily improves low and mid-range torque. Its standout performance in the Mazdaspeed6 earned it a Ward's 10 Best Engines award for 2006 (see WAW — Jan. '06, pp.28).

For comparison, a base BMW 3-Series uses a 3L I-6 that makes 215 hp and 185 lb.-ft. (251 Nm) of torque, and the Mercedes C-Class entry engine is a 2.5L V-6 producing 201 hp and 181 lb.-ft. (245 Nm) of torque.

One must move up to the upper-specification levels in these premium-badge cars to approach the Mazdaspeed6's output.

Mazda engineers say the DISI system also improves emissions and fuel economy. The Mazdaspeed6, despite its impressive engine output, is rated at a respectable 20 mpg (11.8 L/100 km) city and 26 mpg (9 L/100 km) highway.

The vehicle's interior employs soft-touch materials for the IP and good-looking metallic finishes on knobs, pedals and door handles.

Exterior styling cues differentiate the Mazdaspeed6 from a standard Mazda6 with new front and rear fascias, a bulged hood and flared front fenders.

Pricing begins at $27,995 for a fully equipped base model. Only one option package is available, the Grand Touring, which includes Xenon headlights and heated, power seats. A black and white leather-seat scheme is available in the first year. The Grand Touring package adds $1,930 to the base model's price.

The Mazdaspeed6 arrived in mid-November at the 300-odd U.S. Mazdaspeed dealers certified to sell the special car.

The Mazdaspeed6 is an intriguing addition to the existing Mazda6 lineup. Buyers intent on a premium badge may not consider it. But they should, given its formidable performance advantages.