synthetic oil question
Since you sell the stuff, I have a Yanmar diesel, high hours , but runs great still. I want to try synthetic. But notice a viscosity issue in synthetics. I know regular oil car engine viscosities but not what appears to be low weight synthetics. like 5W-40W, 3W-30W? I am used to car oils like 20-40 or for my high performance (runs hot when racing) 20-50W. What should I use for my 75 horse Yanmar sailboat 4 banger? She's 1/2 to 3/4 of the way to diesel heaven. I want her to run smooth, and not make her parts work hard( lower viscosity) but she getting is looser than a bangkok whore in tollerences as she get older so more viscosity may be needed to make up the differnces. I am in southern CA, and plan top go South( warmer climates). What do you recommend?