While fans eagerly await the introduction of the rotary-engine RX-8 four-door sports car, Mazda Motor Corp. has introduced, with way too little fanfare, a sports sedan that replaces its aged and creaky 626 with one of the best cars the Japanese automaker has ever made.

It is called, simply, the Mazda 6, and it is, simply, a family sedan for the enthusiast driver who feels no need to stop having fun while hauling the brood to grandma's for Sunday dinner.

Prices start at $19,050 for the base four-cylinder Mazda 6i and $21,620 for the V-6-powered 6s. Loaded, the 220-horsepower V-6 model tops out about $25,000.

There are sport models in both versions that provide special exterior trim, all-black interiors, 17-inch alloy wheels and a unique instrument cluster.

The sedan is the initial offering, but Mazda promises a wagon version and a five-door hatchback next year.

Though slightly smaller than the Honda Accord, Toyota Camry and Nissan Altima with which it will compete, the Mazda 6 is big enough for four adults or a pair of grown-ups with three smaller folks squeezed into the back seat. A redesigned rear suspension opens up space in the trunk, which is bigger than the Accord's but smaller than the Camry's.

What little the new Mazda lacks in size it more than makes up for in performance -- not just speed but handling, balance, steering, braking and ride quality as well.

Honda and Toyota are celebrated for reliability, and Nissan has made a grab at being the import brand with more muscle per pound than anyone else, so Mazda looked at sagging sales and thought, gee, we were once good at making sporty, fun-to-drive cars -- maybe we should go back to that.

Instead of copying their rivals, Mazda engineers looked at cars such as the Volkswagen Passat, BMW 3-Series and Audi A4 when they started work on the 6.

Mazda's predecessor 626 was nice looking with somewhat generic Japanese sedan styling, but it suffered from too little power, mushy suspension, too few amenities and uncomfortable seating.

The new 6 drops a couple of digits from the name but adds everything the 626 lacks.

There are a few things to complain about: The manual shifter uses a cable linkage rather than mechanical rods, and it seems to hesitate for just a fraction of a second as you shift gears; the bright finish on the plastic in the interior could be toned down; the clunky-looking spoiler on the sport model ought to be an option; and if the car were about 2 inches wider, the rear seats probably would be big enough to warrant the three safety belts that are provided.

But even the entry-level model is nicely furnished with goodies that include 16-inch wheels; front bucket seats; split, folding rear seats; air conditioning; rear heater ducts; illuminated vanity mirrors; cruise control; tilting, telescoping steering column; power door locks, windows and exterior mirrors; and a six-speaker s tereo with in-dash CD player and auxiliary controls on the steering wheel.

A few words about those rear seats and the trunk: There's a lever in the trunk that allows you to flip down the rear seats from back there -- a feature every car with fold-down rear seats ought to offer; and the trunk, even in the base model, is nicely lined with hydraulic hinges that don't intrude into the cargo area. (You won't find those features on Honda's base Accord model.)

Power for the basic 6i comes from a 2.3-liter four-banger rated at 160 horsepower and 155 pound-feet of torque, the pulling power that helps accelerate a vehicle's mass. The 6s with its V-6 engine is rated at 220 horsepower and 192 pound-feet, enough to snap your head back if you pound the accelerator to the floorboards. The engine is tuned so that 90% of the torque is available at 1,750 rpm.

A five-speed manual transmission is standard in both models, with the 6i offering a four-speed automatic as an option nd the 6s an optional five-speed "automanual" that works in fully automatic mode or as a clutch-less manual.

Virtually no one achieves federal mileage standards, especially in a car meant to be pushed hard. Still, the Environmental Protection Agency's fuel economy estimates are worth noting: 25 miles per gallon in city driving and 32 mpg on the highway for the 6i and 20 city, 27 highway, for the 6s. (You can subtract 1 mpg for the optional automatic transmissions.)

Both models have firm suspension tuning -- Mazda engineer Reuben Archilla says the setup in U.S. models is identical to that on models sold in Europe and Japan. The sport models provide bigger tires for a better grip on the asphalt.

The sport trim includes a body styling treatment with flared lower-body skirts, a multi-scooped front fascia, fog lamps integrated into the long, narrow headlamp array (apparently because it was cheaper to make just one style of array, the regular models look as if they have fog lamps, but the housing is empty) and a rear fascia that adds to the ground-hugging look.

On the road and on an autocross course set up by Mazda during the media introduction this fall in Ventura, the 6 fulfilled every promise made by the automaker's marketers.

The car sticks to the road on the curves without tossing driver and passengers all over the inside, accelerates powerfully on the straights (especially with the throaty V-6 howling away) and stops better than anything else in its class. Steering is firm and quick. If the manual transmission were smoother, there would be almost nothing to gripe about.

Final words: At last, here's a real sports sedan for those who don't have $40,000.