Re: Safe to use regular oil in 4 stroke?
You want an oil that meets or exceeds the standards called out for your oil. As long as it does, you are good to go. Oils are generally biased for their application though so read up. I use Amsoil oils for the correct applications in anything important to me. They make specifically formulated oils for each application. If there is any doubt about the Valvoline oil you mention, use the Quicksilver you have been using and go enjoy the boat.
