https://blovish.github.io/kirkslider/

Unless you have a modern microwave with an inverter, which will power the magnetron constantly with varying levels of power.

I don’t know if anyone can really get you that number, because the tax isn’t clearly disclosed when you buy gasoline, it’s just included in the price; the taxes also vary widely between different states/counties/maybe cities too?

Edit: the federal tax is $0.184 per gallon