The document summarizes China Yuchai International's fourth quarter and full year 2012 earnings conference call. It discusses declines in the diesel commercial vehicle market in China but growth in the bus market, where China Yuchai saw opportunities. It notes China Yuchai's increasing sales and leadership in natural gas engines, which are well-suited for buses. While China Yuchai's engine sales and revenue declined from the previous year's quarter, it continued investing heavily in R&D to develop new engine technologies and stay ahead of competitors.