Hyd oil is not often changed so I use only the recommended Kubota filter/hyd oil there. There are outdated hyd oils that "meet", so they claim, but do NOT "equal" the genuine Kubota hyd oil. In particular the 303 hyd oils are NO GOOD! and OUTDATED! Use Kubota UDT down South and SUDT up Nawth.
(If you allow it to warm up properly the UDT will work anywhere for a lot less $)
The engine Kubota filter is not that much more than the aftermarket filters and many popular aftermarket filters are not that good (thinking particularly of Fram which has a BIG name and REALLY POOR QUALITY, and a record of failed and small filter elements, cheap bypass valves, and thin can/crimps that can spill your oil out in the field and you'll hear the engine knocking before the oil pressure light comes on to warn you. AVOID FRAM FILTERs IN ANYTHING you value!) See filter reviews all over the internet and you'll see why.
Most brands of engine oil are good, including the SuperTech (WalMart) which is exactly identical to Quaker State/Pennzoil. If the oil meets the CJ4 then all is good. (In the "old days" when "Pennsylvania Grade Crude" was common...Yes, it was the best. But since WW2 and modern refining technology has prevailed... all the oil comes from all over the world and is dumped into the same vat and cooked/refined and pumped into whichever plastic bottle BP/Mobil-Exxon/Castrol/Shell/Quaker-State/Pennzoil/SuperTech/WhoEver wishes and charges the price according to the brand-label...but it is ALL THE SAME! That's easy to prove also because EPA is so picky about additives and environment that the product is regulated into identicality. In fact, it's possible to read the fine print on some bottles to see that it's actually produced at the same refinery by the exact same refiner and merely marketed by being pumped into different plastic containers with wide-variance of prices accordingly.
Save your money and buy whatever engine oil meets the CJ4 grade (or later) and the correct/recommended viscosity of your Owner's Manual.
