1. (Units) a unit of heat in the fps system equal to the quantity of heat required to raise the temperature of 1 pound of water by 1Â°F. 1 British thermal unit is equivalent to 1055.06 joules or 251.997 calories.
Quick Answer. A major factor that usually causes tire noise is the air chamber inside the tire. The large void that is filled with air acts as a giant resonance chamber. Thus, the tires are something like donut-shaped drums that generate a low-frequency hum when tires are rolling.
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.