I have the same problem. I just purchased a 2018 Ram 1500 with 16,000 miles. The test drive was smooth but, didn't get it on the highway, the hour drive home wasn't bad either. I noticed that the Wrangler SRA's had unusual wear so I replaced with 4 new Kuhmo's which look like the Michelin's and that's when the vibration started being noticed. I bought the tires at Discount Tires, took them to another location and they said that the tires were not balanced, vibration was still there. thook it to another location and they said two tires were out of round, they replaced the tires but, vibration is still there. replaced with michelin's...vibration still there. Took truck to dealership, they said tires were not balanced (BTW every time these tires were balanced they wee road forced) Dealership road forced all 4 but. said there were two which were still in the yellow, had Discount Tire replace two Michelin's in question but, truck still drives exactly the same today as when I started, now I am out an additional $400 for these Michelin's. Like all the rest, the vibration is in my legs, the seat and console at highway speeds. The truck goes back to the dealer Friday, they seemed to be pretty cool to begin with but, service advisor has not returned my wife's texts or calls in two days and he was the one that reached out to my wife first to see if the truck was fixed after it left their dealership the first time. I would also like to note that a 2 year old truck also went in for a back up camera which only worked when it wanted to, a clock on the 8.5" screen that doesn't keep time and a steering wheel heater which already stopped working. They fixed it but, not what I expected for my first Ram. Two friends just bought new trucks, one a Ford and one a Chevy both Crew Cabs like mine, both of theirs have performed flawlessly and ride very smooth. This Sucks ! First time I've had a payment in 20 years and have to deal with this crap !