Overall, the new Skyactiv-G 2.0-liter engine is 4.4 pounds lighter than the existing base 2.0-liter MZR engine, yet it incorporates new dual sequential valve timing (electronically variable) and multi-hole direct injection and makes 155 horsepower and 148 pound-feet of torque. That’s about five percent more power and ten percent more torque than the former 2.0-liter. In the Mazda3, the new engine has a 12:1 compression ratio, yet it uses regular gasoline.
Fitted to the new Skyactiv-G engine is an all-new six-speed manual gearbox, or an all-new six-speed automatic transmission. The manual gearbox has a better, smoother, and quicker shift feel than the previous unit, with nice, light clutch takeup as well. For the automatic, Mazda went with a conventional hydraulic layout but redesigned it from scratch to accomplish the quicker shifting of a dual-clutch system while effectively using the torque converter only for slip from a standing start.
All-new automatic both smooth and quick
The new six-speed automatic is the star of the lineup. Mazda boasted that the much lower slip allows a more linear response, and more predictable driving feel, but we were skeptical until experiencing this in the twisties. The transmission ratchets between gears with the quickness of VW's DSG—well, almost—while pulling off downshifts in Drive seemingly with less indecision. Slip the shifter over to manual, and though we missed having paddle-shifters we were also able to get very quick downshifts, with rev-matching, and it'll hold gears up to redline with no forced upshift or full-throttle-forced downshift.
The all-new engine starts and idles with a smooth purr (Mazda has even redesigned the starter, and all the ancillaries). After a short distance, it was clear that while it's not quite as quick as the 2.5, it has a nice, even buildup throughout the range. There's more available low-mid-range torque than the Elantra, and none of the thrashy, coarse character that some compact cars exhibit when pressed hard. We couldn't find any odd vibrations or resonant frequencies, and it feels like a true premium small-car engine in character, revving freely to redline and responding quickly to throttle blips. We’re also happy that Mazda has dialed some engine braking into this unit.
Springs and dampers have been retuned for 2012 throughout the Mazda3 lineup, with the settings slightly softer, and the net effect is that a little more road harshness has been tuned out. While for road noise the Mazda3 of a few model years ago had one of the noisiest cabins in its class, the redesign of a couple model years ago, combined with the subtle changes this year, mean that there’s no longer such a distinction. The Elantra is quieter inside, no doubt, but next to the now more softly-sprung Civic, it’s a tossup between the two for road noise.
Mazda3 still one of the few that gets steering feel right
The Mazda3’s electro-hydraulic power steering (which combines an electric pump with a traditional hydraulic-boost feel) remains, simply, the best among all compacts—with a confident feel on center, nice, even and progressive weighting off center, and more road feel (with the severe road shocks damped out) through the steering wheel than you'll experience in any other small car. And with most other automakers saying that they had to use motor-drive electric power-steering units (and their often far inferior feel) to achieve those high mileage ratings, it seems like a slap in the face.
And even though the Mazda3i Grand Touring model we were driving for most of the day is hardly the performance model of the lineup (with lesser tires and brakes than the 3s), handling and control is phenomenal, with crisp turn-in and a body that reacts progressively and predictably in quick esses. It's now one of the only models in its class with an independent, multi-link rear suspension. Also standard across the board on the Mazda3 lineup, but not available in most other compacts—at least in the entry models—are four-wheel disc brakes. Mazda3s models still come with slightly larger discs, but no matter the trim, the Mazda3's pedal feel is solid and secure.