Here are my (limited) thoughts on the whole ZDDP/flat lifter thing:
(Disclaimer: i don't know jack about engines and am not a "natural engine person." Yet i manage to get hi mileage out of anything i drive. 300,000+)
For any cheapskates like me, who are still in the stone-age running flat lifters:
My thoughts on oil are as follows: The oil should be considered an integral part of the engine---the oil is a part just like the crank, rods, pistons etc. And not an afterthought. Therefore serious consideration should be given to oil selection and application.
Now, given the small price difference between running a ZDDP sufficient oil vs. whatever oil is on sale at the auto parts store---even if you change every 3000 miles (not even sure if that's still required these days), the difference in money is not that much, wouldn't it make sense to be safe and run a verified ZDDP sufficient oil? It's like cheap insurance.
That is my personal thought regarding oil for flat lifter engines.
i don't think mobil syn 10w-30 has enough. i think certain royal purple 5 and 10-30s have enough and redline 5 and 10-30's have enough.
Given a little while, i can provide links to ZDDP sufficient oils.