synthetic vs. petroleum based oils

This topic was addressed somewhat on another thread but,I’d like to refine it a little and see if there is some sound scientific data available out there.Does anyone know of any neutral party, side by side comparisons between synthetic and petroleum based 2 cycle oils?Any neutral scientific data at all?I am an Amsoil user.I do not work for,have stock in or any other interest whatsoever in Amsoil,other than I do use their products.My knowledge of their products has been limited to,a friend that introduced me to the product,my own experience with it(which has been excellent)and their web-site,www.Amsoil(certainly a biased source).I am not a mechanic.I’m a change my own oil…put new plugs in…maybe replace the starter kind of guy.Much beyond that and it is usually off to the shop it goes.Personally,Amsoil posesses a couple of attributes that I like.#1.It is 100% synthetic,which,could reduce our dependence on foreign oil and perhaps save pristine areas of the world from the despoilation of drilling for oil.#2.More enviromentally friendly.2 cycle engines are notorious polluters and if I can minimize that in my boat,that’s a good thing to me.However,these attributes may not be enough to retain me as a customer,were I to discover something negative about synthetic oil so,anybody……anything? Mike