"Green oil" , whatever name is on the bottle , Kendall , Brad Penn , Penn Grade , DA whatever. For the race engines I change it when it turns color . The late Harvey Crane got me using the stuff almost 50 years ago. "If it's green , it's working , if it's not , take it out". was his words to me. Daily driver , hydraulic roller engines get 5-30 synthetic. Race car hauler gets 20-50 VR1 because you can get it anywhere on the road . Different needs , different oils.