Mazda earlier this year revealed that its 2012 Mazda3 will offer some very significant gains in efficiency.

In fact, it will be the first of Mazda's U.S. models to benefit from the automaker's SkyActiv initiative, which aims to improve fuel efficiency, reduce emissions, and make Mazda products even more competitive.

And now we have some numbers. According to Mazda officials, the 2012 Mazda3, slated to go on sale in October, will be able to achieve an EPA 40 mpg on the highway with either the automatic or manual transmission—without measures like low-rolling resistance tires, reduced sound insulation, or extra-tall gearing. And, says the company, the Mazda3's zoom-zoom driving feel will be very much intact.

Key to those gains will be the all-new SkyActiv-G engine, which will get direct injection, plus a number of clean-slate engineering choices that help save weight, along with pumping and friction losses—and producing 15 percent more torque along with 15-percent reductions in fuel consumption and emissions.

Complementing this new engine will be two all-new transmissions: a six-speed manual gearbox and a six-speed automatic transmission. Both also are significantly lighter and help improve gas mileage about 30 percent altogether while also preserving that more direct feel that the brand is known for.

Price-wise, the 2.0-liter SkyActiv engine will likely slot between Mazda's existing 2.5-liter four-cylinder and the high-performance MazdaSpeed3.

Performance will be decent, though with about 150 horsepower and 155 pound-feet the SkyActiv 3 likely won't be any quicker.

In addition to the much more impressive mileage ratings and improved transmissions for some Mazda3 models, all 2012 Mazda3 models will include a revised (toned-down) front-end appearance, revised rear styling, and new wheel designs.

Stay tuned to GreenCarReports, along with our companion site The Car Connection, for more information about the 2012 Mazda Mazda3, along with driving impressions of the new SkyActiv powertrains.

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