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 stroke cycle of an engine is governed by the crankshaft which serves to regulate the firing order of the cylinders. All cylinders are not on the same stroke at the same time and correct firing order is important to balance engine operation and minimize vibrations. A common firing order for four-cylinder engines is 1-3-4-2 which indicates that cylinders 1 and 3 fire (power stroke)together and cylinders 4 and 2 fire together.

The muffler follows the catalytic converter and absorbs sound to help quiet load exhaust. It is followed by the exhaust pipe which is the final exit point for exhaust gas from the vehicle.

Suspension springs are made with wide gap coils of rigid steel cable and both hold the vehicle chassis up off the ground and absorb energy from wheel movement making for a smoother ride.

The water pump is driven by a belt connected to the crankshaft and ensures that coolant moves through the engine and radiator.