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

Doosan has many facilities throughout the globe that help manufacture 60 different engine models, as well as materials and parts. Products include diesel engines and natural gas engines for forklifts, trucks, buses, construction machines, generators, ships and more. Engines range from 70 to 1,500 hp. Yearly output is now 75,000 units.

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