If you have never seen it, it doesn't mean it didn't exist. You just never looked for it, as the tunnel vision for regular Techron didn't allow it, I guess. The concentrated version is not on the shelves these days, and not available to public, as far as I know. But it was, about 5 years ago. And it was every AutoZone that had it, not just mine. Every single AutoZone, at least in South East of USA, had it on the shelves sitting right next to the regular Techron, regular Techron being the one YOU used and the one that is still available these days. The more concentrated version was $2-$3 dollars more, but because people don't read labels - it didn't sell well, and is now gone in history. It looked nearly identical to the regular Techron, even the same 32oz bottle, just different wording on label and different product inside.