Sunoco 260GTX is developed as a very clean burning and detonation resistant racing fuel. It is used as the control fuel in Grand Am (since January 2006 replacing the Sunoco 260GT) and is designed to not affect fuel bladders (some fuel cell manufacturers have had problems with fuels containing ethanol as the oxygen carrier). Sunoco 260GTX does not contain any ethanol.

Due to its high octane numbers (103RON and 93MON) combined with a relatively high specific gravity of 0.762 kg/litre the 260GTX works exceptionaly well in turbo engines, without air restrictors, and high compression normally aspirated engines.