I don't know how much is 'enough'. But I would guess with the way they promote it, should be more than enough for a driver. Don't know about a race motor...
I understand how you mean. You are probably right. I am unfamiliar with Kendall oils of today. I used it long time ago, like 25-35 years ago, and had no issue with it back then. Struggle finding 15W-40 or 20W-50 for gas engines around here so I went a couple of towns up north and bought it from a place that sells oils sort of half wholesale, but to bigger customers like truck companies and that kind of things.