I'm honestly speechless. As a total newbie I thought I understood the importance of a good oil change, but my mind was blown this morning. I have a 6V 1954 Chevy that's been a little testy while turning over. Sounds a little rough at times, and can all together be a little unpredictable. Today was the day I was going to tackle the oil change, and I discovered the oil was BLACK. Threw in some High Durability Quaker State 10w30 along with a brand new WIX filter... And it's a NEW truck. Fires up instantly, has a perfect idle, and run smoooooooth. I know this is probably obvious to the motorhead but I'm thrilled. Haha learning more everyday.