oil in the breather is not always a sign of blow-by. compression test of my engine is normal pero maraming oil sa breather. I change oil every 8 to 12 mos (maling mali yun ha). I don't notice oil consumption.

Synthetic oils are not manipis but instead , the particles are all uniform size. mineral oils have different sized particles. small particles burn off faster and the larger particles are left. these large particles do not lubricate as well and makes the engine wear faster. that is why synthetic oils are better.