That's right. But when people are talking about ''energy stored in the fuel'' they are ignorant of the fact that the energy is stored in a combination of the fuel and the oxygen.JimC wrote:mm is technically correct to say that it is the combination of a hydrocarbon fuel and a given quantity of oxygen that can be said to have a certain amount of chemical potential energy. However, the availability of the correct amount of oxygen is usually taken for granted, and the energy value of the fuel is simply expressed as kilojoules per kilogram. Thermodynamic considerations then determine the percentage of useful energy that can be extracted from the total.
If anybody thinks the energy is stored in the fuel, they should try driving a car with the air intake blocked off.