What is Tire Balancing?
If you are noticing a vibration at speeds of 45 mph or higher, you may have one or more of your tires that are out of balance. This happens when the distribution of weight for a tire and wheel assembly becomes uneven, which is common because, despite their appearance, tires and wheels are not truly round. When mounted, the slight imperfections of the tire and wheel assembly means its center of gravity is not the dead-center of the assembly. At speed, this miss-match causes a vibration which you may not notice at lower speeds but will become noticeable as you go faster. Tire balancing is the processes of adding weight to the tire and wheel assembly, and/or repositioning the tire on the wheel so that the assembly’s center of gravity matches the center point of the assembly as close as possible.
Typically, if you can feel the vibration in the steering wheel, the tires that are out of balance are on the front axle. If you feel the vibration in the seat, then it’s likely the rear tires that are out of balance. This type of vibration is continuous (not intermittent) though you may only notice it when you hold the vehicle at an exact speed.