Abstract: The specification describes lubricating oil compositions containing an additive comprising normal paraffin and/or iso-paraffins and/or naphthenes each of which have from 10 to 20 carbon atoms. Compositions containing from 0.1 percent to 2 percent by volume are disclosed. The compositions are effective in reducing varnishing, sludging chemical by-products and glazing in an engine. The compositions are also useful in automatic transmissions fluid, gear oils and greases.