User blog comment:Bionicleboy3000/Metal Sonic: The most overpowered robot in fictional existence?/@comment-5159692-20130112190705/@comment-477304-20130112193340

That doesn't sound right, there isn't a Super Saiyan 5 and Goku doesn't go any higher than Super Saiyan 3 in Dragon Ball. It's possible that Dragon Ball Z Kai used a Super Saiyan 5, but I doubt they would go that far off the original source, especially seeing as it never happened in the original Dragon Ball Z anime.