Putting together an additive that will disperse evenly and suspend consistently in a variety of densities (different oils have different densities) is more difficult than you would think. Ed, I don't know why you are so adamant on ZDDP additives. Even if you save three bucks a quart by buying a different
oil, after you buy your additive you're only saving less than $20 on an
oil change. If you need ZDDP, or just want it, then taking that risk is just dumb.
