is there anything i can do to stop the oil use. the tail pipe stays black while in town but goes light grey when i go on a long road trip. is there anything that i can replace in the motor to help this. sorry if there is a post already on line but i couldn't find it. any info would be helpful. ps. what is the best oil that i should use in this truck. using penzoil 10w-30 now. thanks srf.