Start with what a component does, then place it inside its system. Following the movement of heat, power or electrical energy helps you distinguish parts that work together but perform different jobs.
What you’ll learn
Learn the method
In a conventional liquid-cooled engine, which component transfers heat from circulating coolant to passing air: the radiator, water pump or thermostat?
The requested job is transferring heat out of the coolant. Keep that separate from moving the coolant or regulating its route.
Coolant absorbs heat near hot engine parts and circulates through the radiator. The radiator’s tubes and fins provide surface area through which energy transfers to air passing over them.
The water pump circulates coolant. The thermostat regulates flow to the radiator as the engine warms. They support cooling, but the radiator performs the heat-exchange job named here.
The radiator transfers heat from the coolant to the surrounding air.
The water pump is in the correct system, but choosing it answers “what moves the coolant?” rather than “what transfers its heat to the air?” Match the exact function, not just the system name.
Why is engine oil not the best answer to a question about the radiator’s circulating fluid?
Engine oil primarily lubricates moving parts, while the conventional radiator in this example receives coolant. Both fluids can carry heat, but their paths and primary roles differ.
The example teaches one method. Open a concept below when you need a rule or a different type of example during practice.
In a conventional combustion engine, fuel releases energy that moves pistons, and the crankshaft converts their back-and-forth motion into rotation. The transmission changes the speed-and-torque relationship delivered toward the wheels. Each component has a distinct role; an answer about producing rotation is different from one about changing its ratio.
A four-stroke engine cycles through intake, compression, power and exhaust. A spark-ignition gasoline engine uses a spark plug to ignite the compressed mixture; a diesel engine uses compression ignition. Identify the engine type before applying a fact about fuel delivery or ignition.
The cooling system transfers unwanted engine heat away, commonly using circulating coolant and a radiator. Lubricating oil reduces friction and wear between moving surfaces and also carries away some heat. A question about the radiator, oil pump or thermostat tests which system performs the stated job.
The battery provides electrical energy for starting; a starter motor turns the engine during cranking. In a conventional running vehicle, an alternator supplies electrical power and charges the battery. Braking converts motion into heat through friction. These processes involve different components even though they all affect whether the vehicle can move.
Now apply what you know
Try a few questions without opening the solutions, then explain why each answer works. Use scratch paper for calculations and work without a calculator. These original, untimed questions sample the subject; the result is not an official score.
Work through one question at a time. Explain your approach, check the worked answer, then move on. Use scratch paper for calculations.
0 of 12 checked · 0 correct.
Progress is saved in this browser. These original study questions do not produce an official AFQT score.
Answer: D. Outward toward the surrounding drum
A conventional internal-expanding drum brake pushes its shoes outward against the inside of the drum. Moving them inward would increase the clearance instead of producing contact.
Answer: C. A heater core
A heater core is a small heat exchanger that transfers energy from hot engine coolant to air entering the passenger compartment. It does not mix coolant into that air.
Answer: A. Bring the sleeve and gear toward matching rotational speeds
Synchronizer cone friction changes relative speeds before the positive teeth engage. That reduces clash during the shift. It does not alter tooth count or clutch-pedal position; lubrication is present but draining oil is not its function.
Answer: C. Intake duration 230°; overlap 15°
The intake valve opens 10° before top dead center and closes 40° after the next bottom dead center, giving 10 + 180 + 40 = 230°. Around the exhaust-to-intake top dead center, intake opens 10° before and exhaust closes 5° after, so overlap is 15°. Intake closing after bottom dead center is not part of this overlap.
Answer: C. C
Exhaust from the engine flows through C, the turbine. The shared shaft B transfers its rotation to compressor A on the fresh-air side. D cools the compressed intake air and is not the exhaust-driven wheel.
Answer: A. To connect the starter’s rotation to the engine ring gear
P is the starter pinion. Engagement lets the starter motor turn the engine through the larger ring gear; after starting, the drive is disengaged. It is a mechanical power connection rather than a fuel or coolant component.
Answer: C. Camber
Camber is the wheel’s inward or outward tilt from vertical when viewed from the front. Toe is judged from above, while caster concerns the steering axis viewed from the side. The diagram marks the wheel centerline, not the steering axis.
Answer: B. F open; R closed
The filter pressure difference is 500 − 250 = 250 kPa, so F opens. The pump outlet is only 500 kPa above the 0 kPa sump, below R’s 600 kPa threshold, so R stays closed. The valves respond to different pressure comparisons.
Answer: C. A universal joint
A cross-and-yoke universal joint transmits rotation between shafts whose axes meet at an angle. A splined slip joint mainly accommodates axial movement, while a differential and friction clutch have different mechanisms.
Answer: C. 72 mm
At the two dead centers, the crankpin lies the same distance above and below the crank center. The connecting rod’s fixed length cancels when those piston positions are subtracted. Therefore stroke is twice the 36 mm crank radius, or 72 mm; 36 mm is only the throw radius.
Answer: A. Arrangement A only
In A, the injector sprays into the passage upstream of the intake valve: this is port injection. In B, the injector tip enters the combustion chamber and sprays there directly. Both meter fuel, but their delivery locations differ.
Answer: D. 1.3 V
The alternator produces 14.6 − (−0.2) = 14.8 V across its own terminals. The battery posts have 13.5 − 0 = 13.5 V. Their difference is 1.3 V of total external wiring loss: 1.1 V on the positive path and 0.2 V on the return. The other choices omit one path or mishandle the reference voltage.
Before moving on, choose one error you can explain. Rework that question with the solution closed, then revisit the skill in a later session to check what you remember.
Sketch simple paths for intake air, coolant, lubrication and drivetrain power. Name the major component at each step and its purpose. You do not need a detailed repair drawing to distinguish the function of a pump from a filter or a radiator.
If an item specifies a gasoline engine, hydraulic brakes or a particular drivetrain, stay within that model. Real vehicles vary; a general symptom by itself does not establish a unique real-world fault. These questions practice principles rather than replace vehicle diagnosis.
Auto Information is outside the AFQT. On the computer ASVAB it is tested separately from Shop Information, but the results are combined into the reported Auto and Shop score, AS, used in relevant service composites.
The computer test includes unscored tryout questions in selected subtests. The longer time shown is the total for a section with tryouts, not extra time to add. These figures describe the proctored CAT-ASVAB, not untimed PiCAT or our practice sets. See the official questions and timing table and the guide to test versions.
Sources and materials. Subtest descriptions and timing were checked on September 29, 2026 against the Department of Defense’s What to Expect guide, sample questions and score guide. Teaching examples, diagrams and practice questions are independently authored Test Ninjas materials. Test Ninjas is not affiliated with or endorsed by the Department of Defense.