Hate to tell you but the Mobile is not near what it used to be. It has had to change to meet the requirements of the new cars as well. The heavier weight oils are a little better. You better not break in a flat tappet camshaft that has any spring pressure at all on this other stuff.
I am just telling people that there is a difference in the
oil now and they have all changed in the last 10 years. All of the cup teams us to run the Mobile but when they changed it to meet the new requirements starting in about 2000 they all had to change due to new wear problems.
I am just telling you the best
oil that you can run in your engine. It is the same old story, I have used such and such for 25 years and it is the best there is. Well these are different times and most all of the oils of the shelf are junk for your high end engine. These are just facts that I am passing along.
Good luck, Keith