You seem to have a very narrow range for synthetic. Yes, Amsoil, Redline, and Mobile 1 are synthetics. There are many other synthertics as well. No one implied Delo is as good as the top three synthtic oils mentioned above but it is better than some synthetic and some synthetic blend.
If you go to read the fourth message in this thread, you will see "what the facts are". I offer scientific numbers and you like opinions.
Do you know what the definition is for a synthetic oil? Any hydroprocessed oil can be called synthetic by a judge's ruling. It is just up to the manufature how they want to call it. Castrol chose to call its Synthec synthetic (Group III base stock from conventional oil) but Chevron decided not to call Delo synthetic (Group II base stock from contentional oil).
Are you saying Castrol 20W-50 that meets the SJ rating is the same oil as the one meeting the old rating, say SG? Do you sincerely believe that? LOL.