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.degree. F.+ conversion levels ranging from about 20 to 50 wt. %, preferably about 25-40 wt. %, sufficient to produce a crude fraction, e.g., a C.sub.5 -1050.degree. F.+ crude fraction, containing 700.degree. 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.degree. F. and 750.degree. F. which is then solvent dewaxed, and the dewaxed oil is then fractionated under high vacuum to produce biodegradable high performance hydrocarbon base oils.