I spoke with someone at BlackStone labs today bc of my possible contaminated sample I sent. He thinks it should be ok, but wasn't sure. He was talking about the benefits of synthetic oils being primarily the temperature extremes they provide. He said though that for keeping an engine clean, the pertol oils base is better for keeping an engine clean then a synthetic. He said Mobil made aviation oil at one time in the 15W-50 visc. and Continental Airlines engines wear building up lead deposits. But he said you don't hear many people talk about this, but Petro oils do a better job at cleaning then Synthetics. He was extremely nice but this goes against all common opinions. Is this possible?