[justme1969]

less internal drag. Mount a pump on sheetmetal or such and put your 1/2" drill on it, see how fast the drill burns up when circulating water back into a buckett with it.
This hydraulic pump does not lessen its hp drag much in correspondence with rpm. We would actually trim the impellers on race car our car actually cooled better with the reduced flow. I still dont have underdriven pulleys yet they will make even more energy savings.