I have a Craftsman rider with a 20hp B&S Intek. I have had it for 7 years and have always run an automotive filter on it with 15w40 in the crankcase. Starts and runs wonderfully, very economical and powerful. I totaled up my time mowing once; and it was just short of 2 hours. For our mowing season, I don't have enough hours to change the oil per the manual, so I just change both the oil and filter when I put it away for the season. Auto filters are dependable and cheap, HDEO is ubiquitous and inexpensive for such peace of mind.