Took my '23 RX350H for its 5k service. They rotated the tires and I think thats when these vibrations started. Most likely theory is tires are out of balance, any other ideas before I get them road force balanced? From what I read online, typically out of balance tires are not felt if they are in the rear and therefore I think the rear tires from the factory might not have been balanced correctly and when they got moved to the front thats when I could feel it. I could not find any missing weights on the rims either.
at 65 mph, car is perfectly smooth. its only around 78mph+ that you can feel it. Tire pressures are all 35 psi, checked them myself.

 

Not sure why they don't check the balance on the tire when they rotate them. Obviously it takes time and that's money, but it sure could eliminate issuess.

 

Sounds like tire balancing would solve the problem.

 

This is why In never rotate the tires (except while moving). Don't mess with perfection.

 

If the rear tires were out of balance, you'd feel it in the seat of your pants. I too typically avoid tire rotations as the dividends paid are minimal compared to the potential drama.

 

Never rotate the tires if the car is dialed in from the factory. They may not last as long, but the earlier replacement cost is worth the lack of hassle to get the car dialed back in with steering, balance, etc. I am in my 60s now, I've never rotated the tires on any car I've owned.

 

I've always rotated my tires per manufacturer recommendations. Never had it cause an issue. Sounds like rotation just revealed an issue here.