Recycling of used engine oil is a complex, and energy consuming exercise. During the life of a motor oil it is exposed to large quantities of impurities, increase in acidity, depletion of additives, and oxidation. Therefore even with the high cost of crude oil at the moment it rarely makes economic or environmental sense to recycle a used motor lubricant for subsequent use as a motor oil. The best option for re-use is to sell to a specialist such as safety Kleen, who can process the oil and use for non- motor oil applications.