I saw a pour test from Pennzoil awhile back depicting the difference in pour quality between used and new oil, and the used oil wasn't pouring as fast into the beaker. Made me curious about how much oil thickens over time or if it even does it at all? This could be an advertising ploy to get people to change oil more often, oil companies don't make money if people aren't changing oil so they could've froze the used oil and warmed up the new stuff to make it look drastically different. What would cause used oil to potentially thicken up? And would this be a problem in a extreme cold climate like Montana if the oil was getting aged but not quite ready to be changed yet? I ask because my rigs sit outside all winter with no block heaters of any kind and I try to time it where the oil is changed in the spring and fall so I don't have to be laying in the snow in the cold doing it cussing up a blue streak.