The only Imperial German Navy vessel equipped with diesel was the SMS Prinzregent Luitpold, and she was at best a qualified success, being a 20 knot vessel. I'm surprised that this is not know by people who profess to be knowledgeable of the German navy...
From Wiki on Kaiser class battleships propulsion.
"Prinzregent Luitpold was equipped with two sets of Parsons turbines on the outer shafts. It was intended that a single 12,000 bhp Germania 6-cylinder 2-stroke diesel engine would drive the center shaft. However, the diesel power plant was not ready in time to be installed in Prinzregent Luitpold, so the ship sailed with only two shafts.[7] On trials, Prinzregent Luitpold was approximately one half knot slower than her sisters"