A tire is balanced when the mass of the mounted tire is evenly distributed around the car's axle. Out of balance tires can have negative effects on both you and your car. While you simply don't enjoy the vibration you hear and/or feel, the life of your tires can be decreased, as well as the life of the bearings, shocks and other suspension components when subjected to prolonged vibration.

There are two main causes of vibration in your vehicle. If it is speed dependent, increasing as your speed increases, and becoming especially noticeable around 40-45 mph, it is most likely a balance-related vibration. The second possible cause of vibration is that the tire and the wheel assemble isn't exactly round. When the high spots on the tire and the wheel match to each other, it doubles the amount of runout , or "hop." If there is a hop the vibration will not end when you rebalance your tires. A hop can often be fixed by simply loosening the tire on the wheel and turning it 180 degrees, reinflating the tire after relubricating the bead. If the problem persists, rotate the tire another 90 degrees, and again 180 degrees if there is still vibration. Doing this allows for the high spot to be tried at each quarter of the wheel, and at one of the points, the tire should be round. From here, rebalance the tire and test drive to check for remaining vibration. If you still feel it, the problem is either in the tire itself of elsewhere in the vehicle.