I thought Mobil Drive Clean had a fair amount of group I base stocks, hence it's name.
Johnny (I think) had also stated that Super Tech had a high group I proportion, however since its SL update, manufacture has been shifted from the QS subsidiary to Warren Performance Products. From their data sheet, I believe that Warren is all group II or II+.
Johnny (I think) had also stated that Super Tech had a high group I proportion, however since its SL update, manufacture has been shifted from the QS subsidiary to Warren Performance Products. From their data sheet, I believe that Warren is all group II or II+.