Can you put heat in the gas tank of my 2016 sonata
No you cannot heat a gas tank unless it is in an oxygen less environment. Now if your asking about the product “Heat” fuel line antifreeze, then yes you can but only as specified in the instructions, too much and you will create dirveabality issues.
Do you mean Heet, a bran name gas line treatment for removal of water and extreme temperatures? Sure, just follow the directions on the bottle.