A nice hello. My off-road mower has the hydrostat transmission TuffTorq K62/k66. As manufacturer’s specification for the suitable oil for the hydrostat transmission I can only find: SAE 10W-30, API CD “API CD” seems to be an outdated standard. That was my Google research. I did not find any other useful for this. Does any of you know which oil is suitable for this? I have read in the topic API certificate, but here it is always only about engine oils or the term “CD” kan i don’t relate to API anywhere. It’s not about the cheapest oil but about the right one. Thank you for your opinions and possible experiences / expertise.