Sorry if I am starting a new thread on this topic. A couple months ago it seemed that using 15w-40 Rotella was a bad idea. Over the life of my 2004 SN Excaliber I never paid attention to detailed specs, I just always used 15w-40. Some years it may have been Valvoline, some years Rotella. As long as it was 15w-40, that is what I used. So what is the final verdict on this topic. I am about ready for an oil change. Any insight will be appreciated.
Thanks.