I learn more and more every day here and i just recently learned that the oil i was using in my Ford 5.4 didnt meet the Ford spec's! I allso discovered that many of the conventional oils in the 5w20 and 5w30 dont list the Ford WSS-M2C153-H or the more current spec but most of the synthetic blends and full synthetic oils do. Why is this? None of the high milage oils including the Maxlife Syn blend list the Ford specs either. I spent nearly and hour at Walmart reading all the oils on the shelf and decided on Pennzoil platinum 5w20 based on the many good reports on this forum. What would be the problem in using an oil that does not meet Ford specs? I know, too many questions but i would like to know more about this.