I just wanted to note that I have been using Everest oil for about 4 years now. I first came by it at Smyth Automotive in Huber Heights Ohio as the price per quart jumped out at me. At the time I had a Cadillac Deville with a thirsty North* so I gave this oil (10w30) a go to save a buck. I used...
I have an 1998 Cadillac Deville 4.6L N* 45,412 (Original miles). I am the second owner, and it has been well looked after.
My question is this...
Being a flat tappet motor with 300HP do I need to add any Zinc to my oil since it was originally designed for the SH specification?
I've been told...