Thanks for all the replies. I have never bought into oil additives either...however...the guy that has serviced this Avalanche is a certified ASE master tech and is really a straight up nice guy, who has owned the busiest automotive shop for 25 years in the city I live in. I am skeptical yet intrigued at the same time. He printed out all the service and repairs he has done on this Avalanche since it was new and I noticed on the oil changes on the print outs it had Friction Free treatment at every oil change. I had to google it as I had never heard of it ...so it's not like he's trying to sell the additive to me. I might continue it, as it seems at least not to have done any damage in over 162,000 plus miles. It really does idle and run smooth and quiet. Thanks