I bought a Countyline 25 ton hydraulic log splitter. It came filled with fluids. Engine oil level was fine but the hydraulic oil is low and probably needs a gallon. It says it came prefilled with AW-32. Looking at the fluid temp range chart that came with the splitter AW-46 looks to be a better match for Texas. My thought was to top it off with AW-46. After researching it sounds like mixing fluids may be bad due to different additives between fluids. So I figured I should just get more AW-32. Then I got to thinking. How do I know what brand AW-32 they filled it with and what additives it has versus whatever AW-32 I wind up buying to top it off? That put my brain back on the idea of just topping off with AW-46 since it sounds like a guess no matter what I do. You guys are pretty smart on this stuff so I figured I would ask here Even though it’s not a Kubota product. I do own a Kubota though and this question could easily apply to tractors or anything with hydraulic fluid so felt it was appropriate for everyone’s general knowledge.