Mazda Motor Corp. says it plans to reduce the fuel consumption of its global lineup an average of 30% by 2015.

The auto maker says the commitment will entail a “holistic” approach and include the use of lightweight technologies; an upgrade of almost all gasoline engines; a new gasoline rotary engine; new global diesel mills and the “Smart Idle Stop System.”

Mazda’s patented Smart Idle Stop System shuts down the engine while at a complete stop and restarts it once the accelerator is depressed. It improves fuel economy by as much as 7%-8%, Mazda says. The system will first appear on a Mazda vehicle in 2009 in Japan and Europe before being rolled out worldwide.

Also in 2009 is the introduction of an E85 flex-fuel engine that will launch in Northern Europe and North America.

In 2010, Mazda will introduce its next-generation rotary engine, dubbed “16X.” The engine will offer substantially improved performance and economy through the use of direct-injection spark ignition and high-speed combustion technology, the auto maker says.

Beginning in 2011, Mazda plans to introduce new diesel engines worldwide that it says meet the “strictest exhaust gas regulations in each market.”

The engines will feature next-generation direct-injection technology and turbochargers and reduce oxides of nitrogen emissions. They also will achieve fuel-economy improvements of 20%, Mazda says.

From 2011 onward, Mazda’s new gasoline engines will incorporate next-generation direct-injection spark ignition and other systems that will boost power 15%-20% and improve fuel economy some 20%, the auto maker says.

Mazda promises to develop “safe, lightweight, new-generation platforms” that will reduce the weight of new vehicles by 220 lbs. (100 kg) or more by 2011.