Both Deere and Kubota have outstanding hydraulic oils. Pricey, perhaps, but of high quality. The synthetics or synthetic technology, universal tractor fluids are not cheap, but hardly priced so high as to discourage their use. I've tried the various mineral based, cheaper generics and they simply do not perform as well. They work, but generate too much dullness when cold and noisier too. Take that info for whatever it worth to you.