Deutz AG is an internal combustion engine manufacturer, based in Porz, Cologne, Germany. The company was founded by Nicolaus Otto on 31 March 1864, as N. A. Otto & Cie. Otto was the inventor of the four-stroke internal combustion engine. Deutz engines are available in the power range 4 to 500 kW, with air, oil or water cooling and with life expectancy of 20,000 and 30,000 running hours TBO (Time Between Overhauling) on rebuilt and brand-new units. Deutz-powered air-cooled machines are well-suited for many applications since they cannot freeze or boil-over during normal operation.