Mazda took the wraps off of its new gasoline and diesel engines, as well as a new high-efficiency automatic transmission, ahead of the powertrains' official debut next month at the Tokyo Motor Show.

The SKY-G direct injection gasoline engine (first two photos) promises improved torque and fuel economy - up about 15 percent from Mazda's current 2.0-liter MZR powertrain - thanks to the advances. Mazda hasn't said when the SKY-G engine will enter production, but it's a good bet that it will eventually show up in the Mazda3 sedan in North America. We'd anticipate it to crank out around 170 horsepower while achieving around 30 mpg combined in the Mazda3, although the automaker hasn't officially released numbers.

Not likely bound for North America is the new SKY-D clean diesel engine (third and fourth photos). Again boasting upgrades in both power and fuel efficiency, the engine utilizes a two-stage turbocharger, piezo injectors and a redesigned engine block. Mazda says to anticipate fuel economy about 20 percent higher than in its current 2.2-liter diesel.

Finally, the automaker's new SKY-DRIVE transmission helps improve fuel economy five percent on its own. It's apparently a traditional automatic and not a dual-clutch system, though Mazda says that its rapid-fire shifts should give it a similar feel to those race-inspired transmissions used in an increasing number of competitors.