Please help me. I just recently purchased an '05 F-150 with a V-6 4.2L engine, automatic, 2 WD. It has 89K on it. Seems very solid and runs great! I do not know what the previous owner ran as far as oil goes but the dealership (it was Chrysler not the local Ford dealer) used Pennzoil when they changed it. It had been sitting about 6 months before I bought it. I'm told by several local mechanics that Pennzoil makes engines dirty and will cause early failure. Please tell me what oil would be good to use in this truck for the remainder of it's life.