Reporting question for Vacuum Tube - 7591, JJ Electronics

Product:
Vacuum Tube - 7591, JJ Electronics

Question:
I saw the review about the vintage ampeg but I just wanted to be certain..this tube is rated 19W but my amp is only 15W. Would the 19 want to pull too hard on the system or is 4W not gonna make a difference. I know some systems can't handle that much difference but those we low voltage, sensitive electronics