Preparation of multi-grade lubricating oil

Claim 1

A METHOD FOR PRODUCING MULTI-GRADE LUBRICATING OILS BY HYDROCRACKING AT RELATIVELY LOW PRESSURES WHICH COMPRISES CONTACTING A DEASPHALTED RESIDUM CHARGE STOCK HAVING A VISCOSITY INDEX FROM ABOUT 60 TO ABOUT 100 AND A VISCOSITY AT 210*F. FROM ABOUT 60 TO ABOUT 250 S.S.U. WITH A HYDROCRACKED CYCLE HYDROCARBON STOCK BOILING IN THE RANGE FROM ABOUT 400*F. TO ABOUT 1700*F. IN A VOLUMETRIC RATIO OF SAID CYCLE STOCK TO SAID DEASPHALTED RESIDUUM CHARGE STOCK FROM ABOUT 0.1:1, RESPECTIVELY TO ABOUT 10:1, RESPECTIVELY, WITH HYDROGEN IN THE PRESENCE OF A HYDROCRACKING CATALYST AT A TEMPERATURE IN THE RANGE FROM ABOUT 700*F. TO ABOUT 870*F. AT PRESSURES IN THE RANGE FROM ABOUT 800 TO ABOUT 2400 P.S.I.G., AT A LIQUID HOURLY SPACE VELOCITY FROM ABOUT 0.2 TO ABOUT 2.0 AND A HYDROGEN CONSUMPTION IN EXCESS OF ABOUT 750 S.C.F. PER BARREL OF DEASPHALTED RESIDUUM CHARGE STOCK, DEWAXING THE HYDRCRACKED PRODUCT BOILING ABOVE 600*F. TO A POUR POINT BELOW ABOUT 20*F. AND SEPARATING COMPO-