slow cruiser
Regular Contributor
I've been using Rotella T5 15w-40w synthetic blend in my 2001 8.1s, works great, pressure is more stable than the 10w-30w oil that was in them when I bought the boat. I'm thinking of going to Rotella T6 5w-40w full synthetic, any comments. Crusader says synthetic is okay to use, just wondering about the viscosity.