Hello All, I recently purchased a 4-cylinder (a25a-fks) 18' Camry specing 0W-16 oil. Being that this is the first 0w-16 spec'd car in the US (at least that I am aware of), I figured a discussion was in order. The manual states that 0W-20 can be used but must be changed back to 0W-16 at next oil change. I know I am overthinking it, but that is kind of why we belong to BITOG. I changed my factory fill oil at 1000 miles... looked perfectly fine with no metal flakes etc. I've seen before in a factory fill. I also cut open the stock filter... ridiculously clean. I am now convinced that an early drain is not needed. I refilled it with TMGO 0W-16 from the dealer (about $7/QT) and a stock Toyota filter. I have researched as much as I can and just can't get over a 16 grade oil. Again I know I am overthinking, but I just keep wondering about such a light oil at prolonged highway speeds temperature and therefore viscosity-wise. I also am concerned about a 20 grade or 30 grade leading to increased bearing/piston/valvetrain temperatures due to lower flow or tighter tolerances at non-highway engine speeds. Can engines really be built that have such tolerances and oil pathways that a 30 grade oil will be restricted in flow? If so, are these engines what we are now seeing? Is this just a ploy by Toyota to capture market share on oil until/if the big oil companies start mass producing 0W-16? Any other thoughts, research, or recommendations?