Oil Did you know California required catalytic converters be put on marine engines under 500hp starting in 2008? 49 other states followed suit and required they be on 2010 production years and beyond. This change required that the oil industry adjust the oil formulas to be compatible with the catalytic converters. One of the biggest changes was the level of zinc and phosphorus in the oils. Zinc and phosphorus are primarily used as an anti-wear agents or as an antioxidants. Th