Patent ID: 8048833

Claim:
A lubricating oil exhibiting improved resistance to oxidation and deposit/sludge formation comprising a major amount of lubricant base oil and catalytic antioxidants comprising (a) an effective amount of one or more oil soluble dimanganese compounds having the formula [Mn n (Ligand)] 2 , where n is the oxidation state and Ligand is an organic moiety complexing the manganese; and, effective amounts of (b) one or more substituted N,N′-diaryl-o-phenylenediamine compounds having Formula I where R 1 , R 2 , R 3 and R 4 are independently H or C 1 to C 12 alkyl; or, (c) one or more hindered phenol compound having Formula II where R 5 is OH and R 6 is C 1 to C 8 alkyl; or a combination of both (b) and (c).