Offering an early look at what we'll see in Tokyo next month, Mazda has revealed its "SKY" line of advanced engine and transmission designs that will highlight its "Technologies of Tomorrow" display. While reserving some details on the hardware, the automaker did confirm that both the new SKY-G gasoline engine and the SKY-D clean diesel will play fundamental roles in moving Mazda significantly closer to its goal of improving the average fuel economy of the vehicles its sells globally some 30 percent by 2015. Both engines feature numerous design tweaks that help lower internal friction and improve thermal efficiency. The 2.0-liter SKY-G four combines advanced direct fuel-injection and variable valve timing to raise torque and mpg by about 15 percent compared to Mazda's current 2.0-liter four. Fortified with state-of-the-art piezo-electric fuel injectors and dual-stage turbocharging, the new 2.2-liter SKY-D clean diesel produces about 20 percent better fuel economy that the same-displacement diesel it will replace. To take full advantage of these new motivators, Mazda has also developed a trick "SKY Drive" automatic transmission. While retaining the basic elements of a conventional automatic, the SKY Drive unit will contribute a further five-percent boost in mpg and provide far more positive shifting action thanks to a new torque converter, lower fluid requirements and more efficient lockup circuitry.