I once deliberately ran my own uncertified test: I bought a new ā92 Jeep Cherokee with 4.0L straight-6 and used nothing but straight SAE 30 wt Quaker state and Fram filters every 5K milesā¦. until it had somewhere around 120K miles⦠and I noticed that SuperTech was bottled by the same folks as QSā¦. so I switched to SAE30 SuperTech and SuperTech filters (and the occasional Purolator filter when it was on-sale). Those were cheap oil changes.
I never used any other oilsā¦.and that Jeep was totaled in a rear-end accident at 330K miles. It was only JUST beginning to use almost a half-qt of oil between 5K mile oil changes.
Did QS and ST get that car to 330K miles�? No.
BUTā¦. ordinary conventional QS and ST motor oil did not PREVENT that car from making 330K trouble-free miles.
Needless to mention, I am

when I see the hand-wringing, worrying, arguing, etc that goes on between the Amsoil/Castrol/RedLine/etc devotees.