I was at a racing event over the weekend and visited a Brad Penn Oil tent. I asked the salesman, after listening to his description of the oil and what it can do, if I would have any problems running it in a modern engine, seeing it is typically designed for older engines where a high-zinc content is beneficial. After about 2 seconds, he replied that he saw no harm in it, just not sure how the high zinc content would affect the internal parts of my 5.4. None of the other salesmen could give a definitive yes or no either.

I'm not an oil guru and have always used Motorcraft Synthetic Blend 5W-20 in my 2002 5.4 Expedition. Brad Penn has a 5W-20 and thought about trying it, but felt best to ask first before I do any damage to my engine. Any input, pro or con? Thanks!