Throughout this site we use many technical terms, and given the breadth of readership our site enjoys, sometimes we are remiss and incorrectly assume everyone knows what we are referring to. For those that do not, here are some explanations of the technical terms use.
Additive / Additives:
Substance added to fuel, oil, brake fluid, cooling water etc to improve its performance. There are two types, oil and fuel. Oil additives make up about 15% of oil volume and are used to inhibit oil oxidisation (the main reason for oil breakdown) and to clean carbon deposits (detergent additives). The main fuel additive is teteathyl lead which is used for its anti-knock properties; its addition allows octane levels to be dropped without fear of creating mechanically dangerous pre-ignition or pinging.