Mazda Motor Corp. unveiled a new generation of fuel-efficient enginesin a hope to keep its models competitive in an age of high-tech green vehicles.

Mazda’s new engines, known as the Sky series, will be introduced in 2011, so as to boost the average fuel economy of its fleet 30 percent by 2015 from 2008 levels.

The engines will consume less fuel and deliver higher torque, as a result of Mazda’s re-engineering everything from compression ratios and combustion duration to intake volume.

The four-cylinder, direct-injection Sky-G gasoline engine, offered in sizes ranging from 1.3 to 2.0 liters, will deliver 15 percent better fuel economy than current gasoline engines in the same class, Mazda said. The diesel version, the Sky-D, will get a 20 percent increase over today’s offerings.

Both will be mated to a new Sky-Drive six-speed automatic transmission.
President Takashi Yamanouchi is betting on better combustion engines to keep Mazda in the game.

Mazda showed a 1.3 liter Sky-D engine in the Kiyora concept car that was first unveiled last year at the Paris Auto Show. However, it is not clear as to which models will get the new engines first.