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 the year 1975, manufacturing diesel engines on a mass scale at its very first large scale facility. Within 10 years the company's production technology had progressed to the point that production of its very own diesel engine model was possible. Doosan's leadership position within the industry was secured. In 1995 Doosan made its first low-emission diesel engine, followed by commercial vehicle CNG engines after three years. Since 2000, the company has developed technology for Tier 3-compliant engines, low-pressure natural gas engines and sophisticated common-rail engines. To be able follow stringent Euro emission control standards, the company developed a low-emission, heavy-duty diesel engine model during 2007.

Doosan has a lot of facilities throughout the globe which help make 60 different engine models, as well as materials and parts. Products consist of diesel engines and natural gas engines for forklifts, trucks, buses, construction equipment, ships, generators and many more. Engines range from 70 to 1,500 horse power. Annual 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 regulations governing engine emissions has led the company to build a compressed natural gas engine factory in the US in the year 2008, and a joint venture plant within Xuzhou, China. The factory within China would have the capacity to produce 50,000 diesel engines per year, with production scheduled to start in 2011.