The character of the Mazda3 is determined by the engine you choose.

The Mazda3i has a 2.0-liter engine that will produce 148 horsepower if you roar it to 6500 rpm, but it requires that kind of intensity to wring out everything it has to give. The variable valve timing and variable intake length improve torque low in the rpm range. Still, this engine's mission seems to be a low purchase price and good fuel economy rather than performance. EPA ratings are 24/32 mpg City/Highway on regular-grade gasoline for the manual, 23/30 mpg for the automatic. (This is using the new EPA test procedures enacted for 2008 that are designed to more accurately reflect the way most people drive.)

The 2.0-liter is a good choice if you're concerned largely about fuel economy. The engine itself is great, but the Mazda3 is a little heavy, so you need all the power you can get. If you're looking for a combination to crawl in commuter traffic, the wide-ratio four-speed automatic is an acceptable choice. The transmission's semi-manual shifting feature gives the driver some flexibility and can be entertaining.

The 2.3-liter engine, on the other hand, delivers substantial power over a wide range of rpm. Its tractable mid-range punch helps provide good throttle response without the need to shift gears frequently. This character sets the Mazda 2.3-liter apart from its competition; it's more like the big-displacement four-cylinder engines in the mid-size Honda Accord and Toyota Camry than it is like its competition in the compact class.

Counter-rotating balancers, exclusive to the larger engine, substantially reduce vibration, making this a particularly smooth-running powerplant. At the same time, this engine really does its best work above the torque peak of 150 pound-feet at 4500 rpm as it pulls to its peak of 156 horsepower at 6500 rpm; so it, too, needs a little help from the driver's shifting skills to stay in the fat part of the power band. At the same time, the 2.3-liter's EPA fuel-economy ratings are 22/29 mpg City/Highway on regular gasoline.

Both the 2.0-liter engine in the Mazda3i and the 2.3-liter in the Mazda3s belong to Mazda's MRZ family, and feature such sophisticated technology as sequential valve timing (S-VT), variable intake system (VIS), and electronic throttle control. Both the sedan and the five-door are set up to take advantage of the strong personality afforded by these Mazda MZR engines.

The steering with its electro-hydraulic power assist responds crisply and accurately to your command, and the tires afford plenty of grip in the corners.

The brakes are up to the task as well. ABS with electronic brake-force distribution and brake assist are now standard on all models; while Dynamic Stability Control with traction control is standard on 3s Touring and Grand Touring. As a fun-to-drive package, the Mazda3 has better credentials than its competition.

The Mazdaspeed3 is an entirely different product due to its turbocharged engine with direct fuel-injection that delivers 263 hp at 5500 rpm. The Mazdaspeed3 has all the hardware to keep up with so much power, notably a six-speed manual transmission that rips off quick, clean shifts in a way that no other front-wheel drive car can match.

The Mazdaspeed3 is a legitimate 155-mph automobile, with a relatively quiet, calm personality on the freeway. Yet the Mazda is really in its element in the corners, where there are no surprises in the way it handles. The chassis stays balanced and predictable right to the limit of tire adhesion, where the limited-slip differential still delivers optimal power to both front wheels. The Mazdaspeed3 carves through the corners in a way that's distinct from its all-wheel-drive competitors, the Subaru WRX and Mitsubishi Lancer Evolution.