When in doubt always use mid-grade. Additives are like Ford or Chevy. You can use Yamaha ring-free or 28 others. I prefer Sea Foam because it does everything that the others do + it is a real good fuel preservative. Keeping fuel good for 3 years.
The world will not be destroyed by those who do evil, but by those who watch them without doing anything. Remember what He has done and remember that He is not done yet!-- GOD IS GOOD