A note on 5w-30 I run in my Intek 24. The engine will use the lighter multigrade. After top up and 2 hour run the sump is typically down2-3 oz. My take is the thinner oil is cooling better and also getting past the rings but not smoking. Yesterday (93F) the Intek sump oil was 300F for a short while but held 30 psi with this Chevron oil.