I second that, Mike. It is DEFINITELY experimental, just as The Groove is experimental. While we have evidence of amazing things happening, that does not equate to proof. Proof is an individual evaluation.
As to your failure, Mario, how many grooves have you done? How many engines and what were they?
I believe we will find the answer there. It takes practice to make The Groove correctly, and some vehicles (sad to say) just don't want to budge. While we're reducing that number every day, and correcting that in many instances, I suppose there will always be one or two in the mix that won't let us work with them.
My recommendation is to find something in the Ford Truck series from 1998-2003 and groove THAT one.
You will see The Groove works. You must do more than one engine, though! I recommend you do 6 before making a determination of its value to you, or your ability to do it.
Ron