Recycled oil is used oil that has been run through a process of oil recycling that removes particulate and insoluble impurities. Although oil recycling process removes physical impurities in the form of particulate matter from the oil, it does not remove chemical impurities and contaminants. This allows the oil to be reused in the form of fuel or as lubrication in non-critical systems. Recycled oil is generally one-time-use and is not high enough in purity to be used in cars or trucks. Motor oils and hydraulic oils are commonly recycled and can be combusted as fuel for a variety of heating applications such as for boilers, space heaters and for industrial purposes such as for cement kilns or blast furnaces. Recycled motor oil can also be distilled into diesel fuel or marine fuel. Motor oil retains its lubrication ability and properties ongoingly and can be recycled again and again for a wide variety of different purposes. For this reason, recycled oil is positive for the environment, keeping lubricant products within circulation rather than being wasted through disposal or through environmentally detrimental dumping into soil or waterways.