Free ASVAB Automotive Information Practice Test
The ASVAB Automotive Information Practice Test helps you review the car systems, parts, and basic repair knowledge tested on the Auto Information subtest.
You may need to identify an engine part, explain what a cooling or fuel system does, recognize brake and steering parts, or decide which system controls a certain job.
ASVAB Automotive Information Practice Test
Engine Fundamentals and Operation
Which sequence shows the four strokes of a typical four-stroke gasoline engine in the correct order?
A four-stroke cycle follows intake, compression, power, and exhaust.
Fuel Air Ignition and Engine Management
What is the main job of a fuel injector?
A fuel injector meters fuel and sprays it in a fine pattern.
Cooling Lubrication and Maintenance
The radiator is part of which automobile system?
The radiator transfers heat from engine coolant to the air.
Starting Charging and Electrical Systems
Which vehicle system is required to crank and start a typical automobile engine?
The battery, starter, wiring, and controls provide electrical power for starting.
Exhaust Emissions and Engine Sensors
Which exhaust component helps convert harmful pollutants into less harmful substances?
A catalytic converter promotes reactions that reduce harmful exhaust pollutants.
Transmission Drivetrain and Differential
What is the main purpose of an automobile transmission?
The transmission changes gear ratio so engine torque and speed can match driving needs.
Brakes Steering and Suspension
A disc-brake caliper normally contains the:
The caliper supports the pads and contains piston(s) that press them against the rotor.
Tires Wheels and Basic Diagnostics
Which part of a tire seats against and grips the wheel rim?
The bead is the reinforced inner edge that seats tightly against the rim.
Engine Fundamentals and Operation
Where does the air-fuel mixture burn in a gasoline engine?
Combustion occurs in the combustion chamber above the piston.
Fuel Air Ignition and Engine Management
What does an electric fuel pump do?
The fuel pump supplies fuel from the tank to the engine.
Cooling Lubrication and Maintenance
What is the main job of the engine thermostat?
The thermostat helps the engine warm up and then allows coolant flow to the radiator.
Starting Charging and Electrical Systems
What is the main function of the starter motor?
The starter converts battery power into mechanical rotation to crank the engine.
Exhaust Emissions and Engine Sensors
What is the main purpose of a muffler?
The muffler reduces sound produced by exhaust pulses.
Transmission Drivetrain and Differential
In a manual-transmission vehicle, the clutch allows the driver to:
The clutch separates engine power from the transmission for starting, stopping, and shifting.
Brakes Steering and Suspension
Which part rotates with the wheel in a typical disc-brake system?
The rotor turns with the wheel and is squeezed by the brake pads.
Tires Wheels and Basic Diagnostics
Which tire area makes the main contact with the road surface?
The tread is the patterned outer surface designed to contact the road.
Engine Fundamentals and Operation
Which part changes the piston's up-and-down motion into rotary motion?
The crankshaft converts reciprocating piston movement into rotation.
Fuel Air Ignition and Engine Management
What is the purpose of a fuel pressure regulator?
The regulator keeps fuel pressure within the range needed for injector operation.
Cooling Lubrication and Maintenance
Which component circulates coolant through the engine and radiator?
The water pump moves coolant through the cooling system.
Starting Charging and Electrical Systems
What is the main function of the alternator while the engine is running?
The alternator powers vehicle electrical loads and replenishes battery charge.
Exhaust Emissions and Engine Sensors
What does the exhaust manifold do?
The exhaust manifold gathers exhaust from the engine and directs it into the exhaust system.
Transmission Drivetrain and Differential
What is the main purpose of a differential?
The outside wheel travels farther in a turn, so the differential allows different wheel speeds.
Brakes Steering and Suspension
What is the main function of the brake master cylinder?
The master cylinder converts pedal force into hydraulic pressure in the brake lines.
Tires Wheels and Basic Diagnostics
What is one common effect of driving with tire pressure that is much too low?
Underinflation causes extra tire flex, heat buildup, and faster wear.
Engine Fundamentals and Operation
Which component is NOT an internal engine part?
The clutch belongs to the drivetrain, not inside the engine.
Fuel Air Ignition and Engine Management
Compared with the normal stoichiometric gasoline mixture, a 12:1 air-fuel mixture is generally:
A 12:1 mixture contains more fuel relative to air than the normal stoichiometric mixture.
Cooling Lubrication and Maintenance
Why is engine oil used between moving engine parts?
Engine oil forms a lubricating film that reduces friction and wear.
Starting Charging and Electrical Systems
What is the battery's main role during engine starting?
Before the engine runs, the battery is the main electrical source for starting.
Exhaust Emissions and Engine Sensors
An oxygen sensor in the exhaust helps the engine computer determine:
The oxygen sensor reports exhaust oxygen content so fuel delivery can be adjusted.
Transmission Drivetrain and Differential
In many front-wheel-drive vehicles, a CV joint allows the drive axle to:
A constant-velocity joint transmits torque through changing suspension and steering angles.
Brakes Steering and Suspension
If one full 360-degree turn of a steering wheel turns the road wheels 24 degrees, what is the steering ratio?
Steering ratio = 360 ÷ 24 = 15, so the ratio is 15:1.
Tires Wheels and Basic Diagnostics
A vehicle consistently pulls to one side on a level road. Which condition could be a cause?
Incorrect alignment can cause pulling and uneven tire wear.
Engine Fundamentals and Operation
What is the main job of the camshaft in a four-stroke engine?
The camshaft controls intake and exhaust valve timing.
Fuel Air Ignition and Engine Management
The powertrain control module, or PCM, primarily receives operating information from the vehicle's:
Sensors send operating information to the PCM, which then controls outputs.
Cooling Lubrication and Maintenance
Which maintenance service most directly protects internal engine parts from dirty or degraded lubricant?
Fresh oil restores lubrication and the filter removes contaminants.
Starting Charging and Electrical Systems
In a gasoline engine, the ignition coil is used to:
The ignition coil raises vehicle voltage enough to create a spark across the plug gap.
Exhaust Emissions and Engine Sensors
Which system is most directly used to reduce evaporative fuel vapors from escaping into the atmosphere?
The EVAP system captures fuel vapors and routes them for controlled burning.
Transmission Drivetrain and Differential
An automatic transmission commonly uses which device instead of a manual clutch to transfer engine power at low speed?
A torque converter transfers engine torque through fluid in an automatic transmission.
Brakes Steering and Suspension
What is the main job of a shock absorber?
Shock absorbers damp repeated spring movement and help keep the vehicle controlled.
Tires Wheels and Basic Diagnostics
What is a scan tool commonly connected to in order to read diagnostic information from the vehicle computer?
A scan tool connects to the diagnostic data link connector to communicate with control modules.
Engine Fundamentals and Operation
An engine with cylinders arranged in two angled banks is called a:
A V-engine has two cylinder banks set at an angle to each other.
Fuel Air Ignition and Engine Management
A coil-on-plug ignition system usually eliminates the need for:
The ignition coil sits directly at each spark plug, so long plug wires are not needed.
Cooling Lubrication and Maintenance
Where is most engine oil stored when a common wet-sump engine is shut off?
In a wet-sump system, oil drains into the oil pan below the engine.
Starting Charging and Electrical Systems
What is the purpose of a fuse in an automotive electrical circuit?
A fuse protects wiring by opening the circuit when current rises too high.
Exhaust Emissions and Engine Sensors
If the catalytic converter treats pollutants, which component is mainly responsible for reducing exhaust sound?
The muffler reduces exhaust noise while the catalytic converter treats pollutants.
Transmission Drivetrain and Differential
Which drivetrain component carries torque from a transmission toward a rear differential on many rear-wheel-drive vehicles?
The driveshaft transfers torque from the transmission to the rear differential.
Brakes Steering and Suspension
In a rack-and-pinion steering system, turning the steering wheel ultimately moves the:
The rack moves sideways and pushes or pulls the tie rods to turn the wheels.
Tires Wheels and Basic Diagnostics
A scan tool shows a stored diagnostic trouble code. What does the code usually do?
A trouble code identifies a detected system or condition and guides further diagnosis.
VEHICLE SYSTEMS
What Automotive Information Tests
Auto Information measures your knowledge of automobile technology. Strong preparation means
understanding how major vehicle systems work and which parts belong to each one.
Engine
Pistons, cylinders, crankshaft, combustion, and four-stroke operation.
Fuel and Ignition
Fuel delivery, injectors, spark plugs, starting, and charging.
Drivetrain
Transmission, axles, differential, and power delivery to the wheels.
Chassis
Brakes, steering, suspension, tires, and wheels.
CURRENT TEST FORMAT
Automotive Information Test Format
The computer and paper ASVAB handle automotive material differently.
| Test Version | Questions | Time Limit | Approx. Time |
|---|---|---|---|
| CAT-ASVAB Auto Information | Questions 10 scored | Time Limit 7 minutes | Approx. Time About 42 sec |
| Paper Auto & Shop | Questions 25 combined | Time Limit 11 minutes | Approx. Time About 26 sec |
On the paper ASVAB, Auto Information and Shop Information are combined into one Auto & Shop Information subtest.
ENGINE OPERATION
Know the Four-Stroke Engine Cycle
A common four-stroke engine follows the same basic sequence each time it completes a power cycle.
Intake
The cylinder receives the air-fuel charge.
Compression
The piston compresses the charge.
Power
Combustion pushes the piston down.
Exhaust
Burned gases leave the cylinder.
INSIDE THE ENGINE
Understand What the Main Engine Parts Do
HEAT AND FRICTION
Separate the Cooling and Lubrication
Systems
Cooling System
The radiator releases heat, the water pump moves coolant, and the thermostat helps control coolant flow.
Lubrication System
Oil reduces friction, the pump circulates it, the filter removes contaminants, and the oil pan stores it.
FUEL DELIVERY
Follow Fuel From the Tank to the Engine
Fuel tank
Stores fuel.
Fuel Pump
Moves fuel toward the engine.
Fuel filter
Removes unwanted particles.
Fuel injector
Meters and sprays fuel into the engine.
STARTING AND CHARGING
Know the Battery, Starter, and Charging
System
Starting
The battery supplies electrical energy and the starter cranks the engine.
Charging and Ignition
The charging system replenishes electrical energy, while the ignition system provides spark in gasoline engines.
EXHAUST AND EMISSIONS
Do Not Confuse the Catalytic Converter
With the Muffler
Catalytic Converter
Helps reduce harmful pollutants in exhaust gases.
Muffler
Reduces exhaust noise.
POWER OF THE WHEELS
Trace the Drivetrain in the Right Order
Engine
Transmission
Driveshaft / Axle
Differential
Drive Wheels
The differential allows drive wheels to rotate at different speeds during a turn while still transmitting power.
BRAKES, STEERING, SUSPENSION
Learn the Systems That Control the Vehicle
Disc Brakes
The caliper moves pads against the rotor to create friction and slow the wheel.
Steering
Steering ratio compares steering-wheel movement with road-wheel movement.
Suspension
Springs support weight while shock absorbers control repeated spring movement.
TIRES AND WHEELS
Know the Basic Parts of a Tire
Parts to Recognize
Remember the bead
The bead is the inner tire edge that seats against and grips the wheel rim.
IMAGE QUESTIONS
Use a Simple Method for Automotive Diagrams
First identify the vehicle system. Then find one or two large parts you already know. After that, follow the label or arrow to the smaller component.
For an engine diagram, locate the cylinder and piston first. For a drivetrain diagram, locate the wheels and axle before searching for the differential.
MILITARY JOB SCORES
Auto Information Does Not Determine Your AFQT
Auto Information is not part of the AFQT formula. The AFQT uses Arithmetic Reasoning, Mathematics Knowledge, Word Knowledge, and Paragraph Comprehension.
Auto and Shop scores can still be used in service composite formulas for mechanical and technical occupations.
TEST PAGE
Practice Fast Recognition Before Long Calculations
The CAT Auto Information section gives about 42 seconds per scored question on average.
Identify the system
Engine, fuel, brakes, drivetrain, suspension, or electrical.
Find the part
Connect the component name with the job it performs.
Check the diagram
Trace labels after you know the larger system.
Use math when needed
Save more time for ratio or diagram questions.
CURRENT TEST FORMAT
Review the System Behind Every Wrong
Answer
FAQs