Losi has some of the best oil in the business. I would assume it's just a bad bottle. I just checked my oils and the highier the WT the thicker it was like you would think. The only thing that I have noticed about the Losi oil is it is just a touch thinner compared to a different brand of the same weight. For example if I had 30WT Team Associated shock oil, I would need 32.5WT to get the same WT. It's nothing huge just something I have noticed since using Losi oil.