Isooctane is a colorless, flammable liquid hydrocarbon with the chemical formula C8H18. It is a branched-chain alkane and is commonly used as a standard reference fuel in the octane rating system, which measures a fuel's ability to resist knocking in internal combustion engines. Isooctane is often blended with other hydrocarbons to improve fuel performance. In addition to its use in fuels, isooctane serves as a solvent in laboratories and industrial applications. It is produced from the refining of crude oil and can also be synthesized through various chemical processes. Its properties make it valuable in both automotive and chemical industries.