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.
One of the most annoying sources of noise and vibration, and one that is sometimes confused with wheel vibration, is that caused by resonant vibration in the exhaust system. At certain speeds, the natural oscillations that occur in the exhaust may âstack upâ causing the exhaust system to buzz or resonate.