Sensors provide the data necessary for the vehicle's computer to make decisions and monitor everything from simple vehicle information like tire pressure to complexities like the chemical content of an engine's exhaust.

Ignition timing defines the point in time at the end of the compression stroke that the spark plug fires. Measured in number of degrees before top dead center (BTDC), the exact point that the spark plugs initiate combustion varies depending on the speed of the engine. The timing is advanced (the spark plugs fire a few more degrees BTDC) when the engine is running faster and retarded when it's running slower.

The master (brake) cylinder converts pressure on the brake pedal to hydraulic pressure in the brake lines.

In engine lubrication, oil remains in the oil pan until the engine is turned on. It then gets sucked up the pickup tube by the oil pump and pressurized. This pressure is moderated by the pressure relief valve and the oil is fed through the oil filter into the engine to lubricate it.

Because a compressed spring will ex­tend violently, shock absorbers must be used to dampen the spring’s compression and extension cycles. Struts combine the spring and shock into one unit