Cycle oil

Cycle oil is a light lubricating oil suited for use on bicycles and similar devices.^{[citation needed]} It is a liquid residue produced in the petroleum industry when catalytic cracking is employed to convert heavy hydrocarbon fractions remaining from earlier stages of crude oil refining into more valuable lighter products.^{[1][unreliable source?]}

Small oil application device for Singer sewing machines

Catalytic cracking produces petrol (gasoline), liquid petroleum gas (LPG), unsaturated olefin compounds, cracked gas oils, cycle oil, light gases and a solid coke residue. Cycle oil may be processed further to break it down into more useful products; in particular it may be mixed with heavier products and put through the refining process again (recycled).^[2]