take a 10w30 oil, the 10w is the weight/thickness when cold. The 30 is the oil's weight and thickness when hot, right? Well there are a lot of threads that talk about how an oil thins out when hot. Shouldn't an oil go form a 10 weight to a 30 weight as it warms and get thicker? If so then why do I keep hearing folks talk about how an oil is thinning as it warms? I should know this by now!Thanks!