Discloses novel biodegradable high performance hydrocarbon base oils useful as lubricants in engine oil and industrial compositions, and process for their manufacture. A waxy, or paraffinic feed, particularly a Fischer-Tropsch wax, is reacted over a dual function catalyst to produce hydroisomerization and hydrocracking reactions, at 700° F.+ conversion levels ranging from about 20 to 50 wt. %, preferably about 25-40 wt. %, sufficient to produce a crude fraction, e.g., a C5-1050° F.+ crude fraction, containing 700° F.+ isoparaffins having from about 6.0 to about 7.5 methyl branches per 100 carbon atoms in the molecule. The methyl paraffins containing crude fraction is topped via atmospheric distillation to produce a bottoms fraction having an initial boiling point between about 650° F. and 750° F. which is then solvent dewaxed, and the dewaxed oil is then fractionated under high vacuum to produce biodegradable high performance hydrocarbon base oils.