JimB - I switched at 100 hours, because I figured it was plenty broken in at that point ( I had changed my oil at 25 and 50 hours already), and because, well, I just couldn't wait! I have not changed the Super UDT to amsoil yet, but will at the scheduled next change, which I think isn't until 300 hours. I will, at least for now, always stick to Kubota filters, just because I am scared to switch, as I figure there must be some internal features of filters that I don't understand, and that might make a difference ( in other words, just because it fits might not mean it is equal). I have no idea what I shoud use in my front axle (see other post), so have not decided on that yet, but for sure it will be some sort of Amsoil. Have I noticed a difference? No. And likely never will. At 150 hours of use per year I will die before I will wear out the tractor, so in practical terms I bet I could put in straight 30 weight recycled oil, change it every 5 years, and never wear out the motor. I take pristine care of my tractor just because I want to - I bet I will never detect any performance or longevity changes. Most of the tractors I see my farmer neighbors using to do real work, work that puts food on their and everyone elses tables, sit out all year round, look like rust heaps, and most likely do not get their fluids changed as often as my little toy tractor does. Which approach is right, who knows, but I do it because I enjoy it and I enjoy caring for the equipment in as good a way as I know how. From a dollars and cents (and sense also) position I should have bought used, done absolute minimum maintanance, and replace it when it broke with another beater tractor, but like I said this is as much hobby as work for me.
