Mobil 1 15w-50. Plenty of
zinc/phosphorus and superior wear protection. And despite the conflicting opinions you might read here or elsewhere, it is a true 100%
synthetic oil. The base stock argument has been throughly discredited by industry scientists, as well as the contributors, professional and otherwise, of the well known Bob the
oil guy forum. The
oil refining processes, and most importantly the properties of the finished product are what determines if the oil meets the definition and performance of
synthetic oil. To be stuck on the base stock criteria of the oil to determine whether finished product can be called
synthetic, or not, these days is a overly simplistic methodology that doesn't fit the issue, even partially.
I have been using it since 1997 in many vintage cars, mostly Ford powered. About 250,000 miles total with no lubrication issues or breakdowns. These engines were not babied. Numerous high speed endurance runs flat out in 4th gear for as long as a tank of gas would last.
Every engine that was torn down for inspection showed zero wear on all bearings.
Z