Disclosed are methods in which an aliphatic polyether selected from polyalkylene oxides with monomer units having (3 to 6) carbon atoms and polyvinyl ethers with ether groups having (2) to about (8) carbon atoms is added to a hydrocarbon lubricant; such methods in which the hydrocarbon lubricant comprises oxidation products that are dissolved by the addition of the polyether or polyvinyl ether; hydrocarbon lubricants containing a polyether selected from polyalkylene oxides with monomer units having (3) to about (10) carbon atoms and polyvinyl ethers with ether groups having (2) to about (8) carbon atoms; methods of lubricating machines with these lubricants; lubrication systems including these hydrocarbon lubricants; and machines including these lubrication systems.