Revolution on the movement of the car

Hello everyone,

I am not an engineer but as far as I know that what we need the full for the most is to move the weight of the car, so I thought how can we make the car lighter ? By choosing lighter material but we will face 2 problems we either comprmaize the safety or use very expensive material like the carbon fiber, the other way to make the car lighter is to use the same idea of old hot ballon which if we find a new and not expensive way to fight the gravity maybe by heating air or use Hlium gas to make the car the lightest we can so it will need the minimum amount of full,

I know that I didno't use the best scientifc language but I hope at least I made my idea clear,

Best regards,

Mass is mass. You can't change mass by adding hot air, helium or another lighter element.