In 1958, Doosan Infracore began to produce diesel engines and has continued R&D to help stay ahead of the curve in Korea's heavy and material handling industry. Doosan began in 1975, manufacturing diesel engines on a mass scale at its very first large scale facility. Within ten years the company's production technology had advanced to the point that making its very own diesel engine model was possible. Doosan's leadership position within the industry was secured. In 1995 the company produced its very first low-emission diesel engine, followed by commercial vehicle CNG engines after three years. Ever since 2000, the company has developed technology for Tier 3-compliant engines, low-pressure natural gas engines and sophisticated common-rail engines. In order to follow stringent Euro emission control standards, the company developed a low-emission, heavy-duty diesel engine model during 2007.

Doosan has numerous facilities throughout the globe that help manufacture 60 different types of engines, as well as materials and parts. Products comprise diesel engines and natural gas engines for forklifts, trucks, buses, construction machines, generators, ships and more. Engines range from 70 to 1,500 horse power. Yearly output is currently 75,000 units.

The company is continually engaged in expanding R&D capabilities to increase output and expand to more markets. Demand for more stringent policies governing engine emissions has led the company to build a compressed natural gas engine plant in the US in the year 2008, and a joint venture factory in Xuzhou, China. The plant within China would have the capacity to produce 50,000 diesel engines each year, with production scheduled to start in the year 2011.