My question is what are the advantages and or disadvantages to having larger pumps? For example my Grasshopper 428D has hydrogear 21L pumps but I have no idea how my parker wheel motors are rated. I assume the bigger the pump the more power they draw on the engine. What is the determining factor for speed and torque. Someone please explain the correlation between the pumps and wheel motors. Also if anyone knows what size are my wheel motors?