Is thre any information about the Autozone-branded full synthetic oil? It is being sold in the usual passenger car weights, and is labeled as meeting the same API certifications as the Mobil 1, Castrol, and other synthetics. There is some suggestion on Usenet that it may not be made from PAO stock, but rather from refined and processed petroleum base stock. No one has stated however that this makes a difference in the operating conditions encountered in passenger car use, and reportedly a court decided that oils from both stocks may be labeled synthetic. It's also been suggested that all synthetics as a group, are far better than the nearest semi- or non-synthetic oils. As is usual for store-brand things, there isn't much information beyond the label. Given the 30% or more price advantage over the other brands, is there any reason to not use this oil? FWIW, my auto has been running no differently on it than on the recommended Motorcraft semi-synthetic.
PS: For non-US readers, Autozone is a auto parts store chain.