I know there has been so much about this on so many different threads now that it is almost impossible for someone without any expertise to sort it all out. Also, because there are so many threads, I did not know which was best to post to so hence this new one.

I have a 2001 F-350 CC 4X4 V-10 with 2000 miles. Got my first oil change today at the dealer and the invoice says they put in 6 quarts of 5w30, which brought it to the max line on the dipstick. What I was told by the service manager is "to use the Ford recommended oil." I was told that this was because of the “tolerances” of the V-10, not because of improved gas mileage. He said that he did not personally think the thinner oil would make a noticeable difference in mileage. He also said that although he had heard people say that the supposed improvement in mileage was to help Fords mileage rating over all of their vehicles, he said that the super duties don’t get factored in to that anyway so any improvement would be irrelevant. He said that they put in Mobil 1 for a few of their V-10 customers that insist, but that was the only oil other than the 5w30 that they would usefor this engine.

Anyway, this is offered only to add to the body of what people are being told by the dealers out there. I have no real opinion myself, being somewhat unknowledgeable on this sort of thing. I do, however, feel a bit uncomfortable being at the dealer’s mercy, so to speak.

I know the manual has specific interval recommendations etc. but but some of them are longer than I am used to. I think something that would really help me and others without real automotive expertise to feel more knowledgeable would be this. Use this thread to list what you would do for this engine/drivetrain and why. Include lubrication type for engine, transmission, differential etc. and interval times. I know there are many opinions, and I am just interested in seeing them all in one tread, hopefully without a lot of back and forth argument.