Hey everyone, we recently picked up a 93 F-350 work truck and I’m trying to decide what oil to run in it. I normally follow the manufacturer specs but I’m not sure what to make of it. It calls for SAE 30 oil rated CF-4/SG. SG is apparently a defunked rating. Would I just run something like Delo 500 30 weight or Rotella? Or is the manufacture recommendation so out of date it doesn’t matter anymore? Thanks. This thing has a quarter million miles on it already and I want to keep it running. Oh I plan on following the recommended 5000 mile OCI.