ASVAB Automotive Information Practice Test 222804

Questions 5
Topics Coolant, Crankshaft, Firing Order, Independent Suspension, Sensors

Study Guide

Coolant

Modern car engines are cooled by liquid which circulates through the engine block and cylinder heads absorbing excess heat. This liquid is made up of half water and half antifreeze (commonly, ethylene glycol) which both keeps the water from freezing at low temperatures and raises its boiling point making heat transfer more efficient.

Crankshaft

The crankshaft converts the reciprocating motion of the piston into the rotational motion that's used to power the vehicle and its components.

Firing Order

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.

Independent Suspension

Most modern cars use an independent suspension system on the front wheels. This setup allows each of the wheels on an axle to move independently in response to road level variations. Independent suspension offers much better handling and stability when compared to a rigid axle suspension at the cost of being structurally weaker and more costly to maintain.

Sensors

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.