Diesel engine at 120 [Numbers Don’t Lie]

On 17 February 1897, Moritz Schroter, a professor of theoretical engineering at Technische Universitat, in Munich, conducted the official certification test of Rudolf Diesel's new engine. The goal of the test was to verify the machine's efficiency and hence to demonstrate its suitability for commercial development. . The 4.5-metric-ton engine performed impressively: At its full power of 13.4 kilowatts (18 horsepower) the engine's thermal efficiency was 35 percent and its mechanical efficiency reached 75 percent, resulting in a net efficiency of 26 percent. With obvious pride Diesel wrote to his wife, "Nobody's engine design has achieved what mine has done, and so I can have the proud awareness of being the first one in my specialty." Later in that year the engine's net efficiency reached 30 percent, making the machine twice as efficient as the gasoline-fueled Otto engines of the day.