All I've ever used has been Stihl and Husqvarna, both are really sticky and thick. Somewhere along the way I picked up the cheap stuff from Walmart, SuperTech SAE 30. I'm at the end of my Husqvarna and figured I better get the cheap ready, I had no idea it was so much thinner. At first I thought this can't be good, then I realized it might be better in cold weather. After I cleaned, refueled and filled with Husqvarna oil, I started it and the bar struggled to get going. Is it best to switch to a lower viscosity oil for winter?