I can't say with any certainty as I am thinking about one individual and he didn't try 5w30, so unless he tries 5w30 it would be a long time before I can answer that. And even if I did, it might only be one guys engine. I can say that 5w20 was the first redline oil I tried and that killed my tick, but the 10w30 left a minor tick in my truck. The reason why I went to 5w30 to be honest, I was talked into it by all the other guys having success with it. They had tried 5w20 and 0w30 redline and did not have the success as 5w30, so going along with the program I went to 5w30, but I personally had the same success with 5w20 redline. That was only one guys success, whereas the 5w20 failed to kill the tick in other engines, those engines were noticeable better, but still had warm idle tick. The 6.4 is a newer engine and a much smaller group of guys owning them, it may be another 5 years before we have any kind of answers. So when recommending something, I say try what was successful i most engines because if you try 5w20 and it fails to ill your tick you may give up on it, as it costs a fair amount to experiment. Also, over half the guys including myself it can take anywhere from 500 to 1200 miles to kill the tick. And then one day you start your truck and it's gone, that is why the working theory it is the moly and it needed time to plate. Maybe it is, maybe it's something else, but like I said half of the engines that killed took took time, the other half were quiet right away, and roughly didn't work 20% of the time. The other gentlemen that posted his historical battle with hemi tick and lubrication with video's best encompasses the many experiences on the board. Only now with the many long term uoa's are we starting to see the results. We have 2 or 3 more uoa's that will drop into the long term use category coming within 6 mos. It takes a long time to gather the info, and very likely it will have zero effect on the crowd around here that throws shade on any info including long term uoa's, but regardless we are doing this for ourselves and to help guys in the future, so we plow throw past the noise. We have similar noise on our own forum, even though those guys have seen time and time again another member silence their tick, week in week out. Maybe more random guys from bob's will also have success come out from nowhere and you will understand what we all know.