Engine oil is based approximately 90% on (heavy) paraffinic hydrocarbon, which is distilled from crude oil. The other 10% is additives. The length of hydrocarbon chains varies depending on the expected properties of the oil, but the base reserves generally consist of a set of linear and branched compounds limited to C14 to C50. Excess chemicals contain a wide range of substances that improve anti-abrasion, anti-corrosion, anti-foaming, anti-acid and storage properties and viscosity. In fact, these additives are responsible for precise control of viscosity, lubrication and protection against abrasion. For example, magnesium sulfonates help the oil to remove impurities and residues, or zinc disulfide phosphate (ZDDP) is used as an additive to prevent engine wear.