You guys have made me do some research. I've been telling everyone my 2021 TB with 6.2 has AFM. The owners manual even has a page in it for AFM. Coincidentally, it also has a page for DFM. So I pulled out my window sticker and lo and behold, it clearly says Dynamic Fuel Management. As we all know, GM was sued over lifter failure. When lifters fail, we hear stories of only one bank of the engine being replaced, not both sides. This has led to issues later with the other bank on many engines. Before I took delivery of my truck, the dealer called me and told me GM REQUIRED them to replace ALL of my lifters before I took delivery. Further discussions and research has led me to discover whether all or one side is replaced is due to mileage. My truck had 27 miles so all were replaced.
I still heard all the horror stories. So I bought and installed the Pulsar LT to shut off DFM and auto stop/start. I have not had a single issue with my truck. In fact, I beat the snot out of my truck regularly. Wide open throttle is my normal way to drive. I've towed semi trucks while spinning all 4 tires (video posted before). Even though I beat on it, I'm fastidious about my maintenance. So I also have an oil catch can, CAI cold air kit, AWE exhaust and check/change fluids more often than recommend. I now have 23,000 problem free miles. Bottom line is this; use Mobile 1 synthetic oil and change it every 5000 miles (with filter) whether it needs it or not and you will see 200k miles on these engines (that includes the 5.3) without any major issues. Take care of your engine and it will take car of you. I'll post the link to my TB pulling a loaded semi out of the mud if it's requested.