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.
Suspension Problems. Problems in your vehicle's suspension can cause the truck to vibrate. Broken or weak shocks, tie rods, wheel bearings and other components will make your truck's weight distribute unevenly and cause a vibration.