so far I've run valvoline nextgen 5w20, Quaker State Ultimate Durability 5w30, valvoline synpower 5w20, fram synthetic 5w20, valvoline maxlife 10w30, Pennzoil Conventional 5w20 and 10w30, and it currently has castrol syn. blend 5w30 in it. It was noisy on all the valvoline oil, with the maxlife being a little quieter than the others, but that may be due to the thicker viscosity. Quaker State Ultimate Durability wasn't to bad, but not as quiet as Pennzoil conventional, which seems to be the quietest oil so far, but did get noisier towards the end of the run. the fram stuff, which is made by conoco, was quiet too, but after about 3,000miles started getting noisier. The castrol in it now has been noisy from the start. Seems the oils with sodium based add packs like valvoline and castrol are noisier, where as the moly and boron based oils run quieter, but seem to get noisier near the end of an oci. this was why i wanted to try something with titanium in it just to see if there would be any difference. i know noise isn't an indicator of wear, and truth be told, if nothing really makes much of a difference, ill probably stick with valvoline products as they seem to produce good wear numbers, just wanted to experiment a little bit before settling on one oil