I had been running Amsoil SS 0w20 in the past and all I had to pay for was the filter, and that oil seemed to work very well in the Ram. Since then I've been using regular M1 as well as reg Castrol Edge. It may be phsycological, but it seems like the "Hemi Tick" and/or overall engine noise is a little more noticeable with the M1. Now that I have over 100k on the engine, I was looking at a HM version to use and hopefully stick with, but. Don't really know how they all compared. I've used regular MaxLife in the past in other vehicles and it always seems to have a good reputation in the BITOG community, but I want to keep it a full syn in this truck. I've always thought of the Valvoline full syn oils to be inferior to some of the other full syns on the market, and that's why I was hesitant withe the Val Syn HM. I don't know if there is any truth to that or if it has just been something I remember from the past regarding SynPower or whatever Val calls their FS oil the days.
I don't see anything on Valvoline's website that recommends a drain interval. Is the FSHM good for 10-15k like the other brands? The engine calls for 5w20. As I mentioned, I've ran both 5w20 as well as 0w20 in the. The FSHM 0w20 actually has a slightly higher vis at 100°, which seems good, and a higher vis index, so I think that may be the better choice?
Lastly, I usually add a can of LM MoS2 to the oil for pom. It says a 300ml can is good for 5l (5.28qts). This engine required 7qts of oil. Obviously the Mos2 will increase the count in a 7qt sump, but should I be adding a can plus another 114ml , or about a total of 1.5 cans of MoS2 to cover the 7qts?