Currently, the only oil "additive" I use is a General Motors crankcase cleaner that was last produced decades ago and it's pretty darn good. In the past, have used Lucas, Bar's Leak, STP, Seafoam, BGK, etc. and all made zero to little quantifiable difference. In my extremely humble opinion, most oil stabilizers and additive are some combination of snake oil or are simply used to mask an underlying issues(s). Five quarts of oil is expensive enough without having to add a chemical to help the engine better "perform".
#NEVER GIVE UP
#AUDACITY OF HOPE
"Rather not run the risk of offending anyone, so let me just go ahead and offend someone". -PONY MAN
"When you write the story of your life, don't let anyone else hold the pen". -UNKNOWN