When gasoline is burned in an engine Gasoline evaporates new substance are formed mass is lost or mass is gained.?

When gasoline is burned in an engine, it undergoes a chemical reaction with oxygen, resulting in the formation of new substances such as carbon dioxide and water vapor. Although it may appear that mass is lost due to the production of gases, the total mass is conserved according to the law of conservation of mass. The mass of the gasoline and oxygen used equals the mass of the combustion products plus any energy released. Therefore, no mass is actually gained or lost; it is transformed into different forms.