I have this same problem on my 2019 Ram 1500 5.7 (no entorque), except it occurs for me in the 1700-2100rpm range (2000rpm is where it hits its peak). Feels like a phone with a moderate, constant vibration is under the floor and against the accelerator. Outside of this range it is faint or nonexistent. I don’t feel it in the steering, it’s not a tire issue, that feels and sounds different than this. First time I took it to my dealer they brushed it off saying it’s normal, I’m getting ready to schedule another visit bc I think it is getting more pronounced and annoying. Anytime the truck downshifts, it seems to land right around 2000rpm, so I feel the issue a lot. I’ve had the truck 2 months, I’m 500 miles out from the end of my certified comprehensive warranty, I will be pushing the dealer on this bc it gets irritating on long drives, no way it’s normal. If it was simply due to the v8, the vibration should get worse as the rpms increase, not just have an issue in a very small rpm range.