What's the correct pronunciation for Luffy or Rufi? What's the correct pronunciation of his name? Luffy or Rufi?

At the One Piece wikia, it says "Monkey D. Luffy (モンキー･D･ルフィ Monkī D. Rufi)".
This answer needs a premise.

You see, Japanese don't distinguish between the L and R sounds. The L doesn't really exist and the R is not pronounced like in English. It's more similar to the Italian/Spanish R but it's not rolled. Also, FI doesn't belong to the standard Kana — ha, hi, hu (fu), he, ho — but it's constructed.

Based on this, you could say both (and probably for Japanese there really isn't a difference like for us). But apparently Oda meant the name to be Luffy (can't find a source yet), and since the Japanese language cannot faithfully represent this name it became Rufi, being the closest match to the actual name.