I was wondering what a good oil would be to put into my truck and was wondering what everybody else is using. I got a 00 gmc sierra with a 5.3 and ive been using mobil 1 5w30 but i was thinking of changing to the german castrol 0w30 or the mobil 1 european blend 0w40. Anybody have any suggestions? Also Ive been trying to put a picture up so it will show whenever I do a post but its not letting me and Im not even sure if Im under the right thing. Can anybody help me out with that also and if somebody can do it for me if I cant figure it out I can email the picture to them. thanks