The problems with Auto-RX were basically threefold:
1.) People with engines that really had no issues dumping it in and expecting some kind of wowee results and being disappointed their 73k mi Corolla wasn't a Mustang Cobra or wasn't getting 70 mpg.
2.a.) Frank, who as MolaKule states has/had cancer, starting a grassroots company essentially by himself, on the Internet no less, at who knows what age, and going - IMO - overboard in the claims of Auto-RX. In retrospect if he'd kept it simple and qualified (see #3 below) what it reasonably could be expected to do, IMO he'd have less dissatisfied purchasers.
2.b.) I know initially Frank was honoring the money back guarantee, but I think as the volume of purchasers grew, the expectations mounted (which Auto-RX the Co. helped - but certainly was not solely responsible for), the poor use cases grew, and in more than a few cases irrational buyers reported on it, it sounds like he stopped honoring every money back request. How much his cancer/treatments contributed to this, and how much people poisoned the well, along with what Auto-RX themselves were claiming, who knows. I do know I used to read multiple threads and would just shake my head on a users irrationality of their expectations for the product. I'd also read threads where the product could reasonably be expected to work and the user wasn't seeing the results he/she though, and - lets call it odd - responses from Auto-RX would be received.
3.) Crazy expectations of the product. There would be people complaining that baked on hard carbon on the top of the valve covers wasn't magically being dissolved, or why they weren't getting some crazy mpg bump that others had got (in their full synthetic every 5k for the past 70k mi ride that didn't need a bit of cleaning), or why they weren't getting any sludge reduction after running with full synthetic for 700 mi on the clean and Oh I replaced by stuck PCV valve and I'm running synthetic for the Rinse, P.S. I have a coolant leak, why can I still see sludge in my oil fill hole? Auto-RX is good at cleaning out rings when the rings actually have reached a level they need to be cleaned, which is different for every engine and use case (based on variety of factors). It's good at cleaning out softer and somewhat firm sludge slowly in engines that actually have that, providing the oil actually flows to those areas. As mentioned in 2.b., the problem is Auto-RX website went a little overboard in what it was billing itself as, along with people irrationally using the product for their often irrational uses.
The product does work in the areas it can work in, but it will not - or least, will not effectively - in the areas it can't. All the rest of the talk of 100 years of experience or Frank yelled at me and it made me feel bad or etc. is smoke and mirrors and ego stroking.
