Hello all... I read with interest another post that provided a link to a site where a guy rates all the various oil filters. I now have a Napa Gold on my truck. I am now wondering which oil is best? I have heard Valvoline is good, and that Castrol is also. I have heard that Pennzoil and Quaker State have good marketing but aren't. Anyone have the straight dope? What do you all run in your rigs?