I had some vibrations in almost all speeds for about 3 years with my MT tires size 33x12.50x20 Federal Couradia .Not too bad after balance but kept coming back after few thousand miles.Yesterday I replaced them with Thunderer MT tires with the same size.The result was very good and very happy about them.Vibration was completely gone.I have been driving my truck a lot yesterday and today and I really noticed that they have way less noise that my old tires.I will never buy Federal Couradia MT tires anymore.