The 2012 Mazda Mazda3 SkyActiv* is remarkable but the trim level composition can be confusing, so let’s deal with that before we get very far into the details of SkyActiv and the Mazda3.
First, the Mazda3 is Mazda’s most popular vehicle worldwide and in the U.S. comprises nearly two thirds of all Mazda sales. The Mazda3 is available in two body styles, a four-door sedan and a five-door hatchback, and with four engines.
The base engine is the 2.0-liter “MZR” four-cylinder, a sophisticated dohc 16-valve engine rated at 145-hp and available with the five-speed manual or five-speed automatic transmissions already in Mazda’s repertoire (although the engine got a power boost this year). The engine is available only in the four-door sedan in i SV and i Sport trim.
There’s also a 2.5-liter four in the i Touring and the i Grand Touring four-door and five-door configurations, and the 2.3-liter turbocharged engine that powers the performance-oriented MazdaSpeed3 Touring.
Then there’s the subject of this review, the 2012 Mazda Mazda3 SkyActiv. It’s also available as a five-door but we tested the four-door. We weren’t as concerned about body layout, however, although we will note that the five-door has more cargo capacity while the four-door has better aerodynamics. Both four and five door-doors are sleeker than other Mazda3 models, and although SkyActiv is more than just engine, it’s the engine that will be most noticed so we’ll start there.
With the same displacement as the base engine and also naturally aspirated, the SkyActiv doesn’t gain a great amount of horsepower, bumped up only to 155 horses (about five percent) though torque is raised ten percent, up to 148 lb-ft. While both are welcome, it’s fuel economy that’s the big advantage of SkyActiv. Equipped with a six-speed automatic, the Mazda3 SkyActiv has an EPA fuel economy of 40 mpg highway, an increase of 21 percent over the MZR four-cylinder.
The engine, not surprisingly, has direct injection with multi-hole injectors for a better fuel spray pattern. The pistons have a novel face with a deep cavity that, according to Mazda, “ensures a shorter combustion time and suppresses the impact on power and torque from engine knocking.” The system allows a compression ratio of 12.0:1, but even more is possible. Mazda has run a SkyActiv engine at 14.0:1, although that requires premium fuel, and even if it achieves an impressively higher fuel economy, Americans are likely to blanche at an economy car needing to use premium.
The new engine isn’t the only element of SkyActiv, however. Mazda also introduces a pair of six-speed transmissions, one an automatic and the manual. Surprisingly, the automatic gets the better mileage, the manual rated at “only” 39 highway mpg. Still, it’s a huge improvement over the 2.0 MZR which has a 33mpg rating. Because of its poorer aerodynamics, the Mazda3 SkyActiv five-door hatchback loses a mile per gallon in city and highway performance.
The Mazda Mazda3 was restyled for 2012 with a new, less-smiley grille and what Mazda says are “more delicately sculpted forms around the openings on the outside edge of the front bumper and a rounded fog lamp shape (changed from the horizontally wide version” of the 2011 model.
If you say so, Mazda, but it still looks like a Mazda3 to us, which it should because this was only a mid-run refreshing.