I drive a 2011 F-150. I put on aftermarket 20" Fuel Maverick wheels and 305/50/20 Nitto Terra Grapplers after having a 2 inch leveling kit installed this past summer.
I've been struggling with a mild vibration over about 70mph. Up until then there is no problem but once I get to 75mph or so, it becomes pretty well pronounced (passenger seat shaking a little when nobody's in it).
I've had the wheels and tires balanced probably 8 times, alignment checked and verified but it still remains.
I was wondering what it might be and what might be worth asking of my local QuikLane to have them check on.