Automobile or Related Car Terms

The conversion of energy from one form (fuel) into another form (movement): The yacht that Jim owned could be driven by wind power.

1. A measure of the force exerted on a surface: Dr. Smart applied pressure on Jim's wound to stop it bleeding.
2. The force exerted by something pressing or squeezing an area: The tires on a car are under pressure because air, forced into them, pushes against their rubber walls.

The number of times a wheel rotates in one minute: One revolution per minute is the same as 1/60 hertz.

A restraining strap attached to a vehicle seat which is fastened around a passenger: A seat belt is intended to keep a person in place in order to avoid injuries in accidents where the occupant could be thrown against a solid object.

A seat belt improves a passenger's chance of surviving a crash by 50 to 75 percent, mainly by preventing inertia from throwing the person through the windshield. It also spreads the force of an impact over a larger area of the body, making injuries less severe.

A seat belt also stretches which slows the passenger down with less velocity so the body feels less force.

A piston that moves in a cylinder filled with oil or gas which can absorb the bumps in a road: Shock absorbers are part of a car's suspension system.

A measurement or rate of how fast a car is going: A car's speed can be determined by dividing the distance it travels by the time it takes to get to a destination.

An engine fueled by coal or oil that heats water to make steam: In steam engines the steam pushes pistons back and forth to drive one or more wheels.

The contour of a vehicle to give as much resistance to the stream of air while driving: The streamlining of the sports car that Jim bought was smooth with curves designed to reduce drag and to improve performance.

A series of components attached to the wheels of a car to make the ride feel smoother for passengers by reducing the effects of vertical motion as the wheels go over bumps: The suspension includes tires, springs, and shock absorbers.

A hollow tube of rubber, often reinforced with fibers of other material, fitted around the outer edge of a vehicle's wheel and filled with compressed air: Tires are the primary means of pushing a car along by applying the force of friction. To give the car maximum push, tires must grip the surface of streets and highways with the powerful force of "static friction".

As well as maximizing static friction, tires must minimize another kind of friction, called rolling resistance. Rolling resistance happens because tires are repeatedly squeezed underneath where the wheels press on them and stretched at the top when wheels release them.

All that stretching and squeezing wastes energy which could be used to go forward.

A tire is a flexible container of compressed air which supports the vehicle's load: The tire structures and features are important to propel a vehicle forward, backward and side-to-side, stops the vehicle, and cushions the load from road irregularities.

Different parts of tire tread work as a team to keep the car on the road.

1. Blocks in the middle of the tire form the tire's gripping surface or traction.
2. Ribs, which are next to the blocks, also form the tire's gripping features consisting of straight-lined rows of blocks that create a circumferential contact "band".
3. Sipes make the tire bend more to improve handling and consist of slit-like grooves in the tread blocks that allow the blocks to move with added flexibility, and increases traction by creating an additional biting edge.

   Sipes are especially helpful on ice, light snow, and loose dirt.

4. Shoulders add grip when the car is cornering.

   They provide continuous contact with the road while maneuvering as they wrap slightly over the inner and outer sidewall of a tire.

5. Grooves are the drains which the tire squeezes water along as it presses the road and pushes it out to the side.

   A low void ratio groove means more rubber is in contact with the road while a high void ratio increases the ability to drain water.

   Whether a tire has a high or low void ratio depends on the tire's intended use.

6. Dimples are little depressions that are part of the shoulder.

   Such indentations in the tread improve cooling.

7. Belt, the reinforcement layer extending around the outer circumference of the carcass under the tread.

   It acts like an iron hoop in improving the stiffness of the tread area. In the case of truck and bus tires, the belt is more heavily reinforced compared to passenger car tires.

8. Tread is that part of a tire which contacts the road surface.

   The tread consists of a layer of rubber, compounded to suit the application purpose of the tire, and the thickness serves to protect the belt and carcass.

   The tread pattern functions to improve water drainage, providing traction, braking, and cornering characteristics; as well as, a longer tread life.

The measurement of how much force is needed to make an object rotate around an axis: Car engines with high torque can produce a great deal of force to make a car go quickly.

Ridged patterns in car tires that help to increase friction and grip on the road: Mark was told that his tires were worn down so much that he should have new ones with good tread for the winter.