Auto and Shop Information (sometimes combined into one subtest) tests practical knowledge of vehicles and tools. Auto covers engine operation and vehicle systems; Shop covers hand tools, power tools, fasteners, measuring, and safety. This knowledge helps qualify for mechanical and maintenance jobs.
How these questions were selected
These 5 questions were curated by the 247SimpleTests Editorial Team from our Auto Information practice bank. Each was selected because it covers a concept that appears frequently on the real exam and that many candidates find difficult on their first attempt. The full practice test has 25 questions — work through all of them once you've reviewed this guide.
The questions
Question 1
In a four-stroke engine, what are the four strokes in order?
- Intake, power, compression, exhaust
- Intake, compression, power, exhaust ✓
- Compression, intake, exhaust, power
- Power, exhaust, intake, compression
▶ Show full explanation
The four strokes in order are: INTAKE (piston moves down, drawing in air/fuel), COMPRESSION (piston moves up, compressing the mixture), POWER (spark ignites the mixture, forcing the piston down — this produces power), and EXHAUST (piston moves up, pushing out burned gases). ASVAB Auto Information tests engine operation. A memory aid is 'Suck, Squeeze, Bang, Blow' (intake, compression, power, exhaust). This four-stroke cycle is fundamental to how gasoline engines work and is commonly tested.
Source: ASVAB Auto Information — Four-Stroke EngineQuestion 2
What is the main function of the alternator in a vehicle?
- To start the engine
- To generate electrical power and charge the battery while the engine runs ✓
- To cool the engine
- To filter the oil
▶ Show full explanation
The ALTERNATOR generates electrical power and CHARGES THE BATTERY while the engine runs, supplying electricity to the vehicle's systems. ASVAB Auto Information tests vehicle systems. The STARTER motor cranks the engine to start it (using battery power); the ALTERNATOR then takes over, producing electricity to run the car and recharge the battery. If the alternator fails, the car runs on battery alone until it dies. Knowing the alternator charges the battery and powers electrical systems (vs the starter that starts the engine) is commonly tested.
Source: ASVAB Auto Information — Charging SystemQuestion 3
What component ignites the air-fuel mixture in a gasoline engine?
- The fuel injector
- The spark plug ✓
- The piston
- The muffler
▶ Show full explanation
The SPARK PLUG ignites the air-fuel mixture in a gasoline engine, creating the spark that causes combustion during the power stroke. ASVAB Auto Information tests ignition. The spark plug receives high voltage (from the ignition coil) and produces a spark across its gap, igniting the compressed air-fuel mixture. (DIESEL engines have no spark plugs — they ignite fuel by compression heat.) Other parts: FUEL INJECTOR (delivers fuel); PISTON (moves in the cylinder). Knowing the spark plug ignites the mixture in a gas engine is commonly tested.
Source: ASVAB Auto Information — Ignition SystemQuestion 4
What is the purpose of the transmission in a vehicle?
- To store fuel
- To transfer engine power to the wheels and change gear ratios for different speeds ✓
- To cool the engine
- To filter air
▶ Show full explanation
The TRANSMISSION transfers engine power to the wheels and CHANGES GEAR RATIOS to match engine speed to driving conditions (low gears for starting/climbing with more torque; high gears for cruising at speed). ASVAB Auto Information tests the drivetrain. MANUAL transmissions use a clutch and driver-selected gears; AUTOMATIC transmissions shift gears automatically. The transmission allows the engine to operate efficiently across a range of speeds. Knowing the transmission's role (transferring power and changing gears) is commonly tested.
Source: ASVAB Auto Information — TransmissionQuestion 5
What is the function of the brake system's master cylinder?
- To pump fuel
- To convert the force from the brake pedal into hydraulic pressure that activates the brakes ✓
- To charge the battery
- To turn the wheels
▶ Show full explanation
The MASTER CYLINDER converts the force from the brake pedal into HYDRAULIC PRESSURE, which is transmitted through brake lines to activate the brakes at each wheel. ASVAB Auto Information tests the brake system. When you press the pedal, the master cylinder pushes brake fluid through the lines to the wheel cylinders/calipers, which press the brake pads/shoes against the rotors/drums to slow the car (using Pascal's principle of hydraulics). Knowing the master cylinder's role in the hydraulic brake system is commonly tested.
Source: ASVAB Auto Information — Brake SystemAuto and Shop essentials: The four-stroke cycle is intake, compression, power, exhaust ('suck, squeeze, bang, blow'); the alternator charges the battery, the spark plug ignites the fuel, the transmission changes gears, and the master cylinder creates hydraulic brake pressure. For tools: a torque wrench applies precise tightening force, screws hold better than nails (threads vs friction), calipers measure small dimensions precisely, and power-tool safety means PPE and keeping guards in place. Practical, hands-on knowledge is rewarded.
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