The base Millenia's 170-horsepower, 2.5-liter dohc V6 is a tepid performer. It takes more than 9 seconds to accelerate from 0 to 60 mph, which is not quick for a proper luxury sedan.By contrast, the smaller-displacement Miller-cycle engine in the S sprints to 60 mph about 7.5 seconds. Yet it achieves a slightly better EPA mileage rating of 20/28 mpg city/highway.
Mazda's unique Miller-cycle engine has been named one the world's "10 Best Engines" for the last four years by Ward's, an automotive trade journal. It uses a Lysholm compressor (a scroll-type supercharger) to boost intake pressure, along with late intake-valve closing to produce an impressive amount of power without sacrificing fuel efficiency. This system allows this 2.3-liter engine to perform like a 3.3-liter engine, while still retaining the 2.3-liter engine's economy of operation. The result is a vigorous 210-horsepower with the brawny, quick response of 210 pound-feet of torque. Beyond the $3,000 it adds to the Millenia's initial purchase price, the Miller-cycle package has no downside.
Put into action, the Miller-cycle engine makes an authoritative growl. Its torque delivers immediate go-power, yet the front-wheel-drive equipment has been engineered to eliminate torque steer even at maximum thrust. And that's not the case with some of the Millenia's competitors. (Torque steer is a tugging of the steering wheel that occurs in powerful front-wheel-drive cars.) The crisp acceleration of the Millenia S is thoroughly appropriate to a well-balanced luxury sedan. At the same time, this engine is supremely smooth. Power is transmitted through an excellent four-speed automatic transmission.