A method for producing ILSAC GF5 or higher compatible oils from used oil, comprising separating material having a boiling point less than about 350° F. from recovered oil to produce de-volatized oil fraction and light oil fraction. Separating material with a boiling point greater than about 350° F. and less than about 650° F. from the de-volatized oil fraction to produce fuel oil fraction and heavy oil fraction. Separating material with a boiling point greater than about 1200° F. from the heavy oil fraction to produce partially purified oil fraction and residual fraction. Treating the partially purified oil fraction to separate it into purified oil fraction and contaminant fraction. Hydrogenating the contaminant fraction to remove predetermined compounds, further saturating the fraction and thereby creating a saturated oil fraction. Fractionating the saturated oil stream to produce one or more of naphtha fraction, diesel oil fraction and base oil fraction.