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.
Frequently Asked Questions. 1  Q: I can feel every bump in the road when I drive. 2  Q: My car's suspension makes noises when I drive less than 25mph. 3  Q: My steering wheel feels stuck. 4  Q: When I take my hand off the wheel, the car pulls to the left. 5  Q: My car's suspension is starting to make squeak-like noises.