I am on my 4th Hemi, the little one, 2 5.7's, and now a 6.4. Mine was purchased with 71,000 and now have 103,000 just over a year. No tick, no knocks, just really noisy at idle, hot or cold. I started using TC-W3 about 5000 miles ago.1 oz to 5 gallons. My motor is dead quiet. I can hear the serpentine belt at idle rather then clicks and clacks etc. It actually cured the noise on the first tank full. I think a lot of the noise is injectors. I am sure many will find this ludicrous, but I am liking the 1 mpg improvement as well. Anything is welcome when you get 10.5 to 11.5 mpg.