dino oil and ZDDP additives ? anybody

i buy mobile 10w-30 5 qt jug at walmart for about 15 dollars.....I add the zddp additive to it. which is about 8 dollars for small bottle..but I buy about 5 for 37 dollars with free shipping....so it about 7 dollars for the additive...

Been doing that for years now. Run flat tappet solid and hydraulic cams....