ASVAB Test / Practice tests / AI
ASVAB Auto Information practice test
10 free questions · scored as you go · every answer explained
Engines, fuel and ignition, drivetrain, brakes and cooling. Reported together with Shop as the AS score. On the computer-based ASVAB you get 10 Auto Information questions in 7 minutes, about 42 seconds per question. It does not count toward your AFQT, but the services use it to qualify you for certain jobs.
Your score
0/ 10
Practice scores from original questions, not official ASVAB scores. ASVAB Test is not affiliated with the U.S. Department of Defense.
-
AIAuto Information1 of 10
What is the correct order of the four strokes in a gasoline engine?
Show answer
Answer: C. Intake, compression, power, exhaust
The piston draws in the air-fuel mix (intake), squeezes it (compression), the spark fires it to push the piston down (power), and the burned gases are pushed out (exhaust). Remember 'suck, squeeze, bang, blow.'
-
AIAuto Information2 of 10
What does a spark plug do?
Show answer
Answer: C. Ignites the air-fuel mixture in the cylinder
The spark plug fires a high-voltage arc across its gap at exactly the right moment, igniting the compressed air-fuel mixture. Diesel engines have no spark plugs; they ignite fuel with compression heat alone.
-
AIAuto Information3 of 10
While the engine is running, what charges the battery?
Show answer
Answer: B. The alternator
The alternator is a belt-driven generator that powers the vehicle's electronics and recharges the battery while the engine runs. The starter is the opposite: it drains the battery to crank the engine.
-
AIAuto Information4 of 10
The radiator's job is to:
Show answer
Answer: A. Release engine heat from the coolant into the air
Hot coolant from the engine flows through the radiator's thin tubes and fins, dumping heat to the air (helped by the fan at low speed). The cooled coolant then returns to the engine to collect more heat.
-
AIAuto Information5 of 10
The main purpose of engine oil is to:
Show answer
Answer: D. Reduce friction between moving parts
Oil forms a thin film between metal parts so they slide instead of grind. It also carries away heat and holds contaminants until the filter traps them. Running low on oil destroys an engine fast.
-
AIAuto Information6 of 10
The transmission's job is to:
Show answer
Answer: B. Match engine speed to road speed through gear ratios
Engines work best in a narrow speed range. The transmission's gears let the engine stay in that range while the wheels turn anywhere from parking-lot speed to highway speed.
-
AIAuto Information7 of 10
When you press the brake pedal, force reaches the wheels through:
Show answer
Answer: C. Hydraulic fluid in the brake lines
The pedal pushes a piston in the master cylinder, and incompressible brake fluid transmits that pressure to pistons at each wheel. Hydraulics multiply force and apply it evenly — a direct use of Pascal's principle.
-
AIAuto Information8 of 10
A standard passenger-car battery supplies:
Show answer
Answer: A. 12 volts DC
Cars use a 12-volt DC system (six 2-volt cells in series). Many heavy military vehicles use 24-volt systems — two 12-volt batteries in series.
-
AIAuto Information9 of 10
In a turn, the outside wheels travel farther than the inside wheels. Which component allows the driven wheels to rotate at different speeds?
Show answer
Answer: B. The differential
The differential splits engine torque between the two driven wheels while letting them spin at different speeds. Without it, tires would scrub and hop in every turn.
-
AIAuto Information10 of 10
The temperature gauge shows the engine is overheating. What should the driver do first?
Show answer
Answer: D. Pull over safely and shut the engine off
Stop and shut down before heat warps the engine. Never open a hot radiator cap: the system is pressurized and will spray scalding coolant. Turning on the heater (not the AC) can help bleed heat while pulling over.
What Auto Information covers
The facts and methods behind the questions, from the app's study notes. Questions on test day are different, but they test the same things.
Engine and drivetrain
Engine and drivetrain: the four-stroke cycle, fuel and ignition, and how power reaches the wheels.
- Four strokes. Intake, compression, power, exhaust ("suck, squeeze, bang, blow"). Pistons drive the crankshaft (reciprocation → rotation); the camshaft opens valves; the timing belt keeps them synchronized — if it snaps, valves can hit pistons.
- Fuel and spark. Injectors mist fuel; spark plugs ignite it. Diesels ignite by compression heat alone — no spark plugs. Octane measures knock resistance, not power. Black smoke = rich mixture.
- Drivetrain. The clutch disconnects engine from gearbox; the transmission matches engine speed to road speed; the driveshaft (RWD) or half-shafts (FWD) carry power; the differential lets wheels turn at different speeds in corners. Automatics couple through fluid in the torque converter.
Vehicle systems
Vehicle systems: cooling and oil, the battery-starter-alternator loop, brakes and tires, exhaust and diagnosis.
- Cooling and oil. Water pump circulates coolant, thermostat gates it, radiator sheds the heat; antifreeze also raises boiling point and fights rust. Oil cuts friction — the red pressure light means STOP NOW. Overheating: pull over, never open a hot radiator cap.
- Electrical. 12 V DC battery; the starter cranks (big drain), the alternator recharges while running. Disconnect negative first, reconnect it last; make the final jump connection on bare metal away from the battery.
- Brakes, steering, tires. Hydraulic fluid carries pedal force to calipers that squeeze rotors; ABS pulses to prevent skids so you can steer. Check tires cold against the door-jamb label; worn tread hydroplanes. Steering free play = worn linkage.
- Exhaust and diagnosis. Catalytic converter cleans gases; muffler quiets them; cabin exhaust leaks risk carbon-monoxide poisoning. Blue smoke = oil, white sweet smoke = coolant, black = fuel.
Keep going in the app. All 45 Auto Information questions, practice that brings back the ones you miss, and full exams timed subtest by subtest like the real test.
Practice the other subtests
Or take the full free practice test: 30 questions from all 10 subtests, with a rough AFQT estimate at the end.
These are original practice questions; real ASVAB items are confidential. Practice scores are estimates, not official ASVAB scores. ASVAB Test is not affiliated with the U.S. Department of Defense or any military branch.