I don't know why everyone makes such a big deal about the hydro oil. ...as if there are people out there who know MORE about lubrication than the guy who spends his life in a shop in R&D testing and retesting every oil known to man... It takes quite a bit of labor to FLUSH the G2 system out when incorrect lubricant is run in that system. I got a 725G2 that someone genius ran automatic transmission fluid in it. The system was overheating and the oil broke down. Wear was starting to occur on the swash plates. It takes 5 gallons of Grasshopper fluid to flush after manually turning the wheel motors and flushing with SAE30 to get the ATF out. Grasshopper fluid is not $40/qt, get your facts straight --> Retail price is $15.50/qt. or $51.25/gal. I put Grasshopper fluid in my Harley in both the trans and the engine. It actually runs cooler. I still will never understand why people will spend top dollar on a high-end machine like a Grasshopper and install cheap parts and add oil they know nothing about. There is a reason Grasshopper has the smoothest operating machines on the market (with G2 drives) and it's because the hydro's!