The oxidative deterioration of petroleum products (change in physical/chemical properties upon prolonged storage under “ambient” conditions) is a complex, yet fascinating problem. For gasoline and jet fuel, a peroxyl radical chain oxidation mechanism is most likely operative during oxidative deterioration. For oxidatively reactive diesel fuel and asphalt, the available experimental evidence suggests that oxidative degradation is not a classical peroxyl radical chain. It is proposed that ETIO is consistent with the available experimental data for oxidatively reactive diesel fuels and asphalt. This paper will critically review pertinent literature dealing with the oxidative degradation of fuel products with focus upon evidence that illustrates the distinction between ETIO and peroxyl radical chain mechanism of oxidative deterioration.