Its oil and it was a good price when I got it. My F-350 6.0 seems to like it just fine. Exact weight that I needed and works great. I don't go too overboard on the engine oil I buy since on this truck I do more frequent oil changes than any other vehicle I've owned. It is a work truck and with the frequent oil changes I feel like synthetic would burn a hole in my wallet so this stuff is working great for me.