A couple days ago, I decided to change my oil again as the oil looked pretty dark on the dipstick. I have 5,200 miles on the engine and I went to Mobil 1 5W30 and an Amsoil EA15K51 oil filter from the factory fill AC Delco Synthetic blend and factory AC Delco PF48 oil filter at 1,754 miles. At 1,754 miles, the factory fill was tar black, so I felt good getting everything out early. The car felt better with Mobil 1 right after I changed it from the factory fill. Felt like it was protecting better from friction inside the engine, but that feeling wore off rather quickly. After 3,500 miles of driving, the oil was blacker than tar. I mean, BLACK! I don't see how that oil can go up to 10K miles. I know the engine is currently it's in early stages of the break-in process and I drive the car pretty hard, but I was surprised at how dark it was upon draining it. After the oil change two days ago, I started driving the car home and noticed how much smoother the engine ran with the fresh oil. It felt as if there was more of a "cushion" between the moving parts if that makes any sense. Before changing the oil, the car ran ok, but the engine had the feeling that the moving parts inside weren't being protected as well from the friction between all the moving parts. This made me feel as if maybe Mobil 1 isn't such a great oil for my engine. I ordered up a case of Amsoil Signature Series 5W30 and will change to that oil as soon as I can. There are CTS-V owners on the forums with manual transmissions that went to the Amsoil SS 5W30 oil and reported back impressive results of how much better the engine felt during shifts and how the engine felt with the added protection against friction and the Amsoil kept protecting for thousands of miles. It's a matter of time before the Mobil 1 I just put in starts to make the engine feel a bit rough again. Maybe I am just really sensitive when it comes to how engines feel and run. Maybe my engine is just hard on oil as hard as I run it and maybe it needs 3,000 OCIs. I haven't done a UOA as of yet as the engine is still new. I plan on doing it starting at around 10K miles. Any wise words?