my truck has 81k on it. no oil leaks feels strong.what do you guys think is the best oil for it ?ford says 5w20.currently im using castrol HM 5w30 but like i said i do not have any leaks.what is the best regular dino oil?i hear that QS and PENZ are not to great and that the best right know are valvoline and castrol.as far as oil filters all I use is motorcraft is there anything better in the same price range?how about changing to 10w30 I live in north carolina where i guess we get all 4 seasons cold winters and hot summers.is there a lot of difference in 5w20 going up to 10w30?or should i stay in the middle (5w30)i know im asking to many questions but any advice is appreciated TKS