The oil pump for an 03 and a 15 bring up the same part number, same flow rate, etc. There have been no oil passage changes as well.
The pressure from the 06 was also fake, so readings are irrelevant. The only time my oem oil pressure gauge is accurate is 1500 rpm with a warm engine.
Per Cummins OEM fill is Valvoline Premium Blue Extreme 5w-40, as they don't know what climate or season it will be sold in.
Hook a pressure gauge up to the port in the filter housing or the one above the ECM if you want real pressure.
Sorry for the derail.. It really pisses me off how much time and energy Ram puts into fake oil pressure.