The stoichiometric ratio defines the proper ratio of air to fuel necessary so that an engine burns all fuel with no excess air. For gasoline fuel, the stoichiometric ratio is about 14.7:1 or for every one gram of fuel, 14.7 grams of air are required. Too much air results in a lean air-fuel mixture that burns more slowly and hotter while too much fuel results in a rich mixture that burns quicker and cooler.

The fuel injector sprays fuel into the air stream that's being fed into the cylinder head via the intake valve. The timing and amount of fuel are regulated by the powertrain control module (PCM) which is the main computer that controls engine and transmission functions.

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

Spark plugs receive current from the distributor and use it to spark combustion in the combustion chamber of a cylinder.

The transfer case splits engine power between the front and rear axles of four-wheel drive vehicles.