Just now read your posting about 3215 filters. I just changed oil for the first time on my 3215HST. I took the OEM filter into the local NAPA store and gave them the WIX No. 51348. NAPA has these as No. 1348 and I paid around $7 for one. The store clerk said they probably carry all the other filters too but indicated that it'd be better to ID them if I brought them to him for comparison. I haven't done this yet since it's not time for me change the hydraulic and air cleaner filters yet. Hopes this helps you out. If you follow thru, let me know what you find out?