The pressure on the earth's surface caused by the weight of the air in the atmosphere. At sea level, this pressure is 14.7 psi at 32 degrees F (101 kPa at 0 degrees C).

The breaking down of a liquid into a fine mist that can be suspended in air.

A retail outlet that carries one (or in some cases in the U.S., a number of) manufacturer's product line and sells to general consumers and fleet operators. The outlet will also provide service and sell parts for the brand of vehicle that it carries. In some instances, a dealer may dual for another manufacturer's product line.

Vehicles equipped with automatic guidance equipment which follow a prescribed path, stopping at each machining or assembly station for manual loading and unloading of parts.

Automatic chokes use either a heat- or computer-controlled element to turn on and off automatically as needed.

Found in some four-wheel drive vehicles, this allows the driver to engage, or 'lock,' the front axle hubs without leaving the vehicle.

A computerized system that automatically maintains a selected temperature for your car's interior. Also called climate control.

A transmission that shifts its own gears according to the prevailing speed, load, and road condition. Also called automatic gearbox. Operation can be electrical or hydraulic, and require no gear shifting or clutching by the driver.

Four-wheeled passenger motor vehicle having a seating capacity for not more than 10 people including police cars and racing cars but not including ambulances or hearses.

Helps improve the quality of vehicle repair and service through the testing and certification of automotive repair technicians. It is a valuable yardstick by which to measure the knowledge and skills of individual technicians as well as the commitment to quality of the repair facility employing ASE-certified professionals.

Movement parallel to a shaft or bearing bore.

The gear ratio of the differential gearbox. The differential gearbox distributes the engine's power (via the transmission input shaft or propellor shaft) to the wheels. The axle ratio of the differential reduces the revolutions of the transmission input shaft before it reaches the wheels. Typical automotive axle ratios are in the range of 2.71 up to 4.31. The higher the ratio, the faster the engine will rev at a particular vehicle speed. Axle Tramp A form of wheel hop that occurs on cars with live axles, caused by the axle repeatedly rotating slightly with the wheels and then springing back. Gear reduction in final drive is determined by dividing the number of teeth on the ring gear by the number of teeth on the pinion gear.

A shaft that transfers power from the differential to the wheels. A solid or straight axle that allows the movement of one wheel to affect the opposite wheel. A live axle is inexpensive to manufacture and is useful for heavy duty applications.