Back in the '70's my friend and his father had a garage. They had a guy who's car wouldn't start that January, so they towed it in to see whats up. Same thing with the oil. They found out the guy used alot of STP oil treatment. He would pour it in a cold motor, and not start it until he needed to go somewhere. It took at least 2 days with a heat lamp aimed at the pan, for it to warm up enough to drain out.,,,