[Reynoldo]

E=MC ² applies to the amount of energy gained by obliterating mass.
This would be the result of fusion of the atoms involved which leaves you with less mass than you started with. Not the energy release by burning fuel.

[TexasGator]

“E=MC 2 applies to the amount of energy gained by obliterating mass.
This would be the result of fusion of the atoms involved which leaves you with less mass than you started with. Not the energy release by burning fuel.”

It applies to the energy release by burning fuel.