I purchased a 2003 Bobcat S175 last fall for personal use. It had ~1600 hours on it when I bought it and I've put on about 35 hours since then. As you can see I don't use it a lot...mostly light landscaping in the summer/fall and snowplowing in the winter. The filters have the number 1530 written in black marker on them. I assume that is the number of hours the filters were changed at. I am looking for recommendations as to when to change which filters. I'll probably buy a service manual for it, but I'm saving up for some tracks and forks first (anyone got a deal for me?). I contacted my local bobcat dealer and asked for a quote to send someone out and do the filter/oil change for me so I could see how its done...plus pick their brain a bit. But if I get good advice from this forum, I may skip the service call. I'm not afraid to get my hands dirty...I change my own oil, filters, plugs, wires, starters, alternators, etc... on my vehicles, but the bobcat is a new animal for me. I found a thread on here that recommended Wix filters. Their prices look good...anyone have a bad experience with Wix? Thanks in advance.