well, hell....times change. I guess as silly as it may seem on the surface, with the new auto tech evolving & thus the market or "what's on the shelf" thus evolving this is worth revisiting. I set up habits of castrol gtx 20w50 in the 90s for my Fiats & I don't think I paid close attention (including a number of years when I was mostly doing other stuff..so, hey, not changing a whole lot of oil anyway). So, I've got some Rotella t4 in the workshop, I have some zinc additive bottles I could add to some recent oil changes (one w/ castrol....because I've always bought the stuff rather in mass, so I have probably 5 oil changes worth of oil & filter "in stock"). Looks like for off-the-shelf purchase of oil with lotsa zinc (which, frankly, I did not think about until rather recently) VR1 is simple enough & a quick look locally demonstrated that a gallon jug is about $30 (with tax) around here, so oil changes would not be changing my lifestyle.