Something that puzzles me is the low hour to oil changes on say Kubota and Caterpillar. Caterpillar hydrostatic like an excavator - first oil change at 4,000 hours. Hydro pumps, motors built by same suppliers. Is it that Kubota does not clean up their components as well at the start? Having inspected so many Caterpillar systems after test cycles I might expect that, especially after seeing the magnetic particles on the filter magnet (Cat doesn’t use such a magnet). However, particles on the magnet mean they didn’t go through the system. Caterpillar machines must meet a certain hydraulic oil cleanliness spec before a machine can be shipped, but at my plants the machines rarely failed this final inspection. I have Blackstone Labs analyze my hydraulic and engine oils when I change. Their analysis always shows oil very good, contamination very low, keep doing what you are doing. I know Caterpillar spends a lot developing their filters. I have had the unfortunate duty of telling people their use of a substitute brand resulted in their failure - you pay - but this is from testing the filters, not just seeing the off-brand and using it as an excuse.