Iso-octane has octane number of 1002, 2, 4-Trimethylpentane, also known as isooctane or iso-octane, is an organic compound with the formula (CH3​)3​CCH2​CH(CH3​)2​ . It is one of several isomers of octane (C8H18). This particular isomer is the standard 100 point on the octane rating scale.