Well, if you read this rubbish: http://www.ttalk.info/Zddp.htm you would think that zddp is 'killing cars' and that the big major car co's were in on the 'secret' so only their motors had the right stuff to be saved.

Millions of cars still use flat tappets (its called something like inverted bucket cam) look at this picture and show me how this is NOT a flat tappet: https://www.highpowermedia.com/RET-Monitor/3079/hydraulic-tappets

There is ONE exception... if you are using high lift cams or double valve springs (aka very high performance valve train components) with a flat tappet then you will need a much higher quality oil with a lot more additives.

Even when ZDDP is included in the oil the ZDDP breaks down very quickly and its not the ZDDP that protects the wear surfaces, but byproducts of the ZDDPs breakdown.

If you have to run MMO in an motor your motor is broke enough to need fixing. You can cover it up with goo in a bottle, but if adding MMO, Unicorn pee or the tears of orphans into the oil would somehow fix something it would be triumphed by the big companies... but to date, as far as I know, there are NO approved oil additives for production cars.

That statement alone speaks volumes.