3-Methylpentane is a branched alkane with the molecular formula C6H14.

It is a structural isomer of hexane composed of a methyl group bonded to the third carbon atom in a pentane chain.

It is of similar structure to the isomeric 2-methylpentane, which has the methyl group located on the second carbon of the pentane chain.

As of early 1990s, it was present in American[3] and European[4] gasoline in small amounts, and by 2011 its share in US gas varied between 1.5 and 6%[5] It has close research and motor octane numbers of 74.5 and 74.3.

This article about a hydrocarbon is a stub.