I use Synthetic Oil... keeps the engine clean, quiet and runs smooth. Oil for the most part stays clean. Use regular coventional oil and it seems to burn faster, turn darker quickly and builds up sludge in my opinion. If anyone wants to differ on my statement... go ahead, I've worked for Mobil and took there certification course. I've seen plenty of cars running synthetic and non-synthetic oil and what the oil looks like 3,000+ miles of use.

Run synthetic... I usually run Mobil 1 but lately I've gone to Castrol. The oil filter I use is FRAM unless I feel the need to go K&N. Once you run synthetic oil you will need to keep using synthetic oil. You can't go back and fourth between conventional and synthetic.