Being my 1st Ford that I own, I was hoping to get a feel for what was the "best" oil was to use in it. I guess it a toss up between mobil1 and castrol. But I might just stick with pennzoil. Had great luck with it in all my chevy trucks along with my pathy. 150,000 on every chevy 1985 and 1989 2.5l iron duke engine before selling them for upgraded vehicle and 128,000 on the pathy. which I still have and no oil leaks or burnoff. But I also change it at 3000 miles. I had used synthetic changing the filter at 3,000 and adding a half qt for what was in the filter and doing a complete oil and filter change at 6000. Oil looked great at 3000 miles but 4500 started getting dark and by 6000 it was black. Something else I do is run a qt of cheaper oil thru to just flush anything that was left behind. What we have found in running oil synthetic or "your dad" oil is that the longer you go the more the fuel dissolute the oil and it breaks down the viscosity. Not talk about the contaminants like metal shavings, and traces of anti-freeze. I would said if you go more than 4000 miles on traditional oil you are bond to have problem down the line. and 6000 miles on Synthetic. Is it worth saving a hundred dollars and taking a change of it costing you more in the end? like a cost of a engine? We at the shop that I work at are required to change the oil at every three of our gas and small diesel engines and 6000 miles on our big diesel engines. We havent lost an engine do to premature engine failure. We have had engine fail but due to faulty parts. we are averaging over 500,000 miles on a transit bus motor. almost 180,000 miles on our gas powered vans. that not including idle time. Sorry this is just my opinion after being in the transit maintenance business 24 yrs and legally driving for 26 yrs...