A British thermal unit (Btu) is a standard unit of energy that is used in the United States and sometimes in the U.K.
There is another defect in tires that can cause a vibration called loaded road force variance. The tires and pass a visual inspection, a radial and lateral runout test, be perfectly balanced, but still cause a vibration. This is due to the internal defects in the tire.
If the tires of a vehicle are not rotated as often as recommended, road noise is sometimes the result. Car owners need to rotate the tires to ensure that all four tires wear evenly. Many manufacturers recommend tire rotation after every 5,000 to 10,000 miles. Lastly, improper inflation causes tire noise.