So I might sound crazy but I have purchased two 5qt bottles and 8 single quarts of Pennzoil Ultra over the last year and have noticed that both 5qt jugs and most of the individual quarts have had visible oil residue originating from the top/lid area, they are still sealed but it seems like this oil likes to "creep" it seems, it got me thinking, I do know esters have am affinity to metal, but that doesn't really explain its affinity to creeping up the neck of a plastic the bottle, I've used many different oils over the last 2 years, (castrol edge, mobil 1, trop-artic, maxlife blend) and none seem to do this, does anybody have a theory on this? tell me I am not a crazy person.