Originally Posted By: ram_man
mobil is just as good and cheaper. this is an easy decision for me to make.
At this point there really is nothing that really differentiates PYB, Valvoline, MS5K, QS, Castrol GTX, Kendall GT-1, Havoline, or Chevron Supreme. I'm all for experimenting, but as I heard one person once say it might be better to simply pick one brand and stay consistent. Something about a better likelihood of additive compatibility.
Of course even these days additives change all the time even with the same exact brand name and most definitely do on a change to the next API service category. Heck - I remember when I bought four bottles of Kendall GT-1 with exactly the same label and API service category. Two were very different. Two had a "sweet" odor, while two had this acrid sulfur-like odor (like most motor oil these days) and a darker color. I figured they probably reformulated, but decided to use them together anyways.