Skyactiv is Mazda’s new approach to automotive efficiency. The heart of the 2012 Mazda 3 models we drove was their new high-compression Skyactiv gasoline direct-injection fours. Using direct injection, reduced back pressure and a number of other technologies, Mazda engineered this system to operate at a compression ratio of 14:1. That’s unheard of in a mass-produced compact car. However, U.S.-spec Mazda 3s with Skyactiv will get only a 12:1 compression ratio because of two factors:
Nonetheless, even at 12:1, the 2.0-liter four goes from 148 peak hp to 155 hp, while torque increases 10 percent to a 148-lb-ft peak and goes up 15 percent in mid and low ranges. Fuae economy goes up by 21 percent to 28 mpg city/40 mpg highway with the six-speed automatic.
Both six-speed manual and six-speed automatic transmissions are thoroughly revamped for more efficiency, too.
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