Originally Posted by highlandchef
No offence, but I might suggest that you get your information from sites that are not advertising a product. Synthetic oils are not just more highly refined mineral oil. If you notice at the top of the page it starts, "Synthetic motor oils - such as Mobil 1". The kicker is the "such as". Mobil1 is a Group III oil which is derived from mineral oil through a process known as hydro cracking. It is not actually a synthetic oil but for marketing purposes in the US it is referred to that way. It is not considered synthetic in Europe. Group IV and V are not made from mineral oil and are true synthetics which are "built" from polymers and esters. Royal Purple and Amsoil are examples of oils using Group IV and V oils. I'm not saying that Group III oils are bad I'm just clarifying the technical info; Mobile 1 is a fine oil but technically it is not a true synthetic. I believe originally it used to be primarily a Group IV oil.
How did you come to this conclusion about Amsoil? They say on their own site that they do not divulge thier base stock and that the only thing that matters is performance. I am not taking offense, just trying to figure out how we actually know that Royal Purple and Amsoil are actually any different than Mobil 1 or any of the other lesser "synthetics" that you speak of.