I'm not an oil expert (and I'm sure there are some guys here pretty good), but I will assume that because synthetic is thin then mineral, it will 'leak' in a bigger quantity to the pistons then the mineral.wjpatter said:I have a 99 and changed to synthetic oil for the first time last oil change. Without exception, I blow smoke to the first two – three minutes. This is new. With non-synthetic oil, I would occasionally blow smoke, maybe one out of ten times. I been reading the threads for a while and don’t remember seeing any correlation between smoke and synthetic oil. I’d be interested in other experiences.