Amsoil is synthetic and provides much better lubrication than the Strikemaster oil. Therefore, it can be ran at a higher ratio. It burns much cleaner also, which reduces the amount of residue. When you first make the switch, there will still be black residue coming out of the muffler. It's only the residue that's inside the muffler and after a tank or two it will be cleaned out. You will not ruin your auger by running Amsoil at 80:1. It will run better and start easier. And a cap full of seafoam doesn't hurt either.