|MLA Citation:||Bloomfield, Louis A. "Question 1188"|
How Everything Works 20 Apr 2018. 20 Apr 2018 <http://howeverythingworks.org/print1.php?QNum=1188>.
However, if you trap the air underneath the car, so that its volume can't increase, and then heat that air, its pressure will rise. This increased pressure below the car would produce an overall upward pressure force on the car and could support the car's weight. In effect, you would be creating a ground-effect hovercraft in which the elevated pressure of trapped hot air supports the weight of the vehicle. But it would be easier and less energy-intensive to pump air underneath your hovercraft with a big fan. That's what most ground-effect vehicles do. They pack extra air molecules underneath themselves and then allow those molecules to support their weight. Furthermore, because air molecules are always leaking out from beneath the vehicle, you'll need a fan to replace them anyway.