An enlarged version of the popular Mercedes D III engine.
An example of engineering extremism. To increase power, the displacement of the existing Mercedes D III engine was enlarged. Two cylinders were added, creating an 8-cylinder giant. Problems with fuel supply and strong crankshaft vibrations appeared. The idea was abandoned, and the short production run of these engines was used to power the Albatros D.V aircraft.
| Configuration | 8-cylinder, inline |
| Cooling | water |
| Displacement | 19.7 l |
| Power | 278 hp |
