2 stroke-4 stroke discussions can be argued either way, but they will all be 4-strokes before long. What got my interest is using $600 of oil every year. Optis, when running correctly, use 100-1 (or even less oil, depending on RPM) ratio when at cruise, way less at lower rpm's. Even at $32/gallon, that is somewhere around 2000 gallons of gas. I wonder if your engine was stuck in the "break-in" mode, which meters heavier oil injection.