On my post above I suggested to go to our website at hustlerturf.com and look up the part numbers and the service manuals. Hydro pumps create a lot of heat. Even though I'm a big fan of Mobil One the 10W30 will be a stretch in Ohio. In the service manual on around page 4-3 it suggest using Mobil One 15W50. I'm not good with 10W30. You'll be fine with just changing the oil, the filter can stay.