TRDUSA2002, you may be absolutely correct. Thank you for you comments.
I agree that it is interesting to note how many will go how far to attempt improvements in a product that has been developed after millions if not billions of dollars have been spent to develop that product assumably to perform at it's optimum. The pros and cons of whether or not acetone is detrimental to components of the fuel system is as good a subject for debate as the notion as to whether or not using it makes any improvement in the operation in what it is being used, or as to why removing the silencer and adding a dropin K & N is thought by many to improve performance. The silencer is also a product of that same high dollar research.
I think that it is a bit unreal to expect high mpg from a pickup, especially one that is used for any kind of chores such as hauling or towing. My interest is more in deriving a little more umph from my 4.6L as it is marginally weak for my use. However, it is what I have and it has no payments. With that in mind, a little acetone here and a little heavier oil there may produce that little extra for which I am seeking.
Additional research in this same forum offers support for both thinner and heavier oils. Some argue that using a heavier viscosity oil should be related directly to a heavier work load while others argue that Ford has improved the performance of their 5W20 to the point that thinner is better. I do not know which is the case.
I am leaning to the notion that Ford's recommendation of 5W20 is mighty close to what my research suggests that I should use. However, since I have added the two quarts of SAE 40 to my 5W20 and installed a new filter, I will run it a couple of thousand miles just to discover the results. Who knows? There may be a little more umph in this combination or the whole kit and kaboodle may come unglued untimely soon. I'll just have to wait and see. As to the acetone, I'll have to wait and see about that as well.
As always, compliments to all for an excellent forum.
George