Spark plug wires are the thick cables that bring spark from the distributor cap to the spark plugs.

An instrument that indicates a vehicle’s speed.

Springs absorb road imperfections and vibration, help hold the suspension up, and help vehicles handle better.

The stabilizer bar is a suspension system component that helps a vehicle to stay flat and not lean excessively when cornering. Also called a sway bar or anti-roll bar.

This is the electric motor that turns your engine over when you turn the key in the ignition switch.

This is a large relay that controls the operation of the starter motor.

The starting system consists of the starter motor, starter solenoid, battery, ignition switch and ignition key.

The steering lock is a theft prevention device that locks the steering wheel in place when the key is removed from the ignition switch.

Shock absorbers are part of your vehicle’s suspension and contribute to your vehicle’s ride quality. They also regulate how much your vehicle moves up and down after going over a bump.

A relay is like an automatic switch. When power is applied to a relay, an internal switch closes, completing a circuit.

Reservoir is a generic term that refers to any container for a fluid. For instance, most vehicles have a windshield washer fluid reservoir and a brake fluid reservoir.

When your car is in park or neutral and you press on the gas without the intention of making the car move, you are revving the engine.

Rheostat refers to a control which varies the intensity of the lights and speed of certain accessories that it is connected to. For instance, an instrument lighting rheostat controls the brightness of the instrument lighting.

When driving along, if you rest your foot on the clutch pedal, you are riding the clutch. This practice causes excess wear on the clutch and the clutch throw-out bearing.

Rocker arms are used in overhead valve (OHV) engines. They are operated by pushrods and open and close the valves.

A rotary engine does not have pistons or cylinders; instead, it has triangular shaped rotors that move in an elliptical path within chambers to create power. The only companies that have offered rotary cars for sale are Mazda, NSU, and

A rubbing compound is a type of paint polish that contains extremely fine abrasive particles. These particles remove the top layer of paint, revealing the shiny layer underneath.

This is a condition that occurs when too much gas and too little air is being fed to the engine. A sign of rich running is black, sooty exhaust.

Rust-converting primer is a special type of primer that stops the progress of surface rust.

Rear-Wheel Drive (RWD). Rear wheel drive cars transmit power to the ground through the rear wheels.