Several commercial processes for reclaiming used lubricating oil were duplicated on a laboratory bench scale. Laboratory tests were selected and in some instances modified to determine the physical properties of each oil produced. In addition, the hydrocarbon composition of some samples were determined using a liquid chromatographic technique and compared with the composition of new oil to determine the severity of the re-refining technique. Selected samples of reprocessed oil were reformulated with an additive package for further estimates of quality as determined by wear, corrosion, foaming, and oxidation stability tests. Additionally, several samples of commercially re-refined oil and new oil were obtained, and physical properties were determined for comparative studies.