03/07/2008 23:09. YOKOHAMA, Japan--Mazda Motor Corp. aims to boost average fuel efficiency 30 percent in the next seven years with new and reworked engines.

The company will upgrade almost all its gasoline engines by 2015 and roll out a stop-start idle system, a gasoline rotary engine, and new diesel engines. Plans to trim 220 pounds from all new vehicles starting in 2011 will help Mazda achieve the goal.

Seita Kanai, Mazda's research and development chief,... // CNET News