Ok ok. So Ive been working around cars for a long time but I'm new to the "Science" of the oils. I've always been a fan of SOPUS products as they've seemed to work very well. Anyway getting to the point at hand. I haven't heard much about formula shell synblend 5W30. Is it any good? I have a stash of about 230 quarts that I got for FREE through a dealership I used to work for. Just wondering the quality of the product. And also what you all typically keep in your stash and how much? Also Autozone in my area has P4 Ultra for 34.99 with filter (idr what kind)Is that a decent deal as well?