Rather than introduce another typical sedan to replace the 626 and Millenia mid-size sedans in 2003, Mazda decided to go sporty. The result was the Mazda 6, a sport sedan that was not only more powerful than the cars it replaced, but also sleeker in design and more nimble over the roads.

The four-door Mazda 6 was available in two configurations for 2003. Under the hood of the base 6i sedan was a 160-horsepower, 2.3-liter inline four-cylinder engine (offering 35 more horsepower than the four-cylinder engine in the previous year's 626 sedan). Stepping the power level up a notch was the Mazda 6s sedan, which was equipped with a 3.0-liter V6 that pumped out 220 horsepower (up 55 horsepower from the V6 in the previous year's 626).

A five-speed manual transmission was standard on both sedans, while a four-speed automatic was optional on the 6i and a five-speed manual was an option on the 6s. Both automatic transmissions had a special gate feature that enabled drivers to shift manually, similar to Porsche's Tiptronic transmissions.

Standard equipment on both 6 sedans included air conditioning, power windows, power door locks, cruise control, dual airbags, and a tilt/telescoping leather-wrapped steering wheel. The upscale 6s added a power-adjustable driver's seat, anti-lock brakes, and traction control. A sunroof and leather seats were among the options.

Generally, drivers liked the Mazda 6's handling, acceleration, sporty suspension, and styling. A few drivers reported having problems with the cars, but those drivers seemed to be the exception rather then the rule, with most reporting little or no problems with the car.