Mercury 2 Stroke Oil

[Intuition Gloucester]

I have been using a bit more oil than usual this season on my 2000 Mariner 135. A bit smokey but nothing that would lead me to believe there are any major problems. I usually use the Mercury 'premium' 2 stroke oil. The last time I bought oil West only had the Mercury 'standard' oil, so I bought it and poured it in. My oil consumption is back to normal and there is hardly any exhaust. Maybe the premium was too rich? Thoughts?