The federal government doesn't collect gasoline taxes under the authority of the income tax amendment, at least as far as I know.
Read the entire amendment. It's not just about how taxes are collected, but it also concerns how they're spent.
“Read the entire amendment. It’s not just about how taxes are collected, but it also concerns how they’re spent.”
Are we talking about the same thing?
The entire amendment as far as I can find it:
AMENDMENT XVI
The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.