It is not printed on the bottles. Have to read the fine print at the web sites of the oil companys and even then some don't say.
Mobil sued Castrol over syntech labeling and lost. The judges loosely defining the word synthetic. Hydrocracking makes the length of the oil molecules even like synthetic Group IV oil. I don't know enough about oils to explain it farther.
Edmunds.com forums talked about it for a long time.
http://townhall-talk.edmunds.com/WebX?ed_displayMakeModelRelatedDiscussions@184.DZB cbDKrNjT.0@.ee9203e!Z=G1gH31gNEb39oXCOsIzjVJ0SVvYK NsMr0nhHcgEroTMYrq/igFRmtesEsLY0npysEVXlYPSx8m2Ot/nbyIn9eT97zwyUpvRW&conflimit=Maintenance%2520%2526 %2520Repair&make=CATS&model=Oil
A few posts in the forum at bobistheoilguy talk about it too.
http://www.bobistheoilguy.com/