I'm generally not brand loyal, but over the past 3 or 4 decades I've bought a lot of Phillips 66 lubricants, mostly conventional oils for my automobiles and pickups. This is due to great prices from my local P66 Distributor.
For synthetic oils, I've used M1, PP, QSUD, but now I'm using Kendall GT-1 Max in my pickup and my wife's auto. I'll be putting GT-1 Max into my younger daughter's car next.
My very outspoken and stubborn eldest daughter insists on M1 in her car. Advertising works.