Mazda has begun mixed-model production at its Ujina engine plant near its headquarters in Hiroshima.

The new production line now makes both the new 3.7-litre V6 and the current 1.8 to 2.3-litre in-line four-cylinder MZR engines. The V6 will be used in the 2008 CX-9 crossover, scheduled to go on sale in North America later this summer.

The line was redesigned to accommodate 'mixed model production', which aims to achieve both diversity and high efficiency by applying the latest production and manufacturing technologies to various engine parts, including the cylinder block and head, crankshaft, camshaft and connecting rods, as they move along the line.

Specific jigs and tools that previously had to be changed for the different engines have been replaced with generic equipment. The result, Mazda said, is a consolidated process that requires less investment in equipment and supports flexible production.

"Achieving mixed model production for the V6 and in-line four cylinder gasoline engines at the Ujina plant is the first step toward volume and model mix flexible production, which lies at the heart of Mazda's concept of manufacturing innovation," said Masaharu Yamaki, the car maker's senior managing executive officer in charge of production and business logistics.

"Going forward, Mazda will progressively introduce the latest techniques to its facilities in Japan and overseas, as part of its manufacturing innovation. We will continue to support improvements in production that raise the brand value and enhance our business efficiency."