ASVAB practice test

ASVAB Auto and Shop Practice Test

Engines, systems, tools and shop practice. Here are 10 ASVAB auto and shop information questions, each with the answer and the reason.

Updated 2026-11-14 by the Tigertest team. Covers eight of the CAT-ASVAB subtests in test order with the real time limits. Assembling Objects uses figures and is not included. Minimum AFQT scores vary by branch and change with recruiting needs.

1. 1.

   What is the function of the alternator in an automobile?

   • A.

     To start the engine

   • B.

     To charge the battery

   • C.

     To cool the engine

   • D.

     To mix fuel and air

   Answer: B.

   The alternator is driven by the engine and generates electricity to recharge the battery and run lights, ignition and accessories. The starter motor turns the engine over; the battery alone powers the car only until the alternator takes over.

2. 2.

   What is the correct order of the four strokes in a four-stroke gasoline engine?

   • A.

     Intake, compression, power, exhaust

   • B.

     Compression, intake, exhaust, power

   • C.

     Intake, power, compression, exhaust

   • D.

     Power, intake, compression, exhaust

   Answer: A.

   The piston draws in the air-fuel mixture (intake), squeezes it (compression), the spark ignites it and drives the piston down (power), then the burned gases are pushed out (exhaust). The mixture must be compressed before it can deliver a power stroke.

3. 3.

   What does the thermostat in an engine's cooling system do?

   • A.

     Pumps coolant through the engine

   • B.

     Filters dirt from the coolant

   • C.

     Regulates flow to the radiator

   • D.

     Stores excess coolant

   Answer: C.

   The thermostat stays closed when the engine is cold so it warms up quickly, then opens to let coolant flow to the radiator. The water pump moves the coolant and the overflow reservoir stores extra.

4. 4.

   Tire pressure should be checked when the tires are

   • A.

     hot, right after a long drive

   • B.

     spinning with the engine running

   • C.

     lifted off the ground on a jack

   • D.

     cold, before the car is driven

   Answer: D.

   Driving heats the air inside the tire and raises the pressure, so a reading taken hot will be several psi too high. Manufacturers' recommended pressures are cold pressures.

5. 5.

   What is the purpose of a catalytic converter?

   • A.

     To reduce exhaust pollutants

   • B.

     To increase engine horsepower

   • C.

     To muffle engine noise

   • D.

     To cool the exhaust gases

   Answer: A.

   The catalytic converter uses platinum and other metals to change carbon monoxide, hydrocarbons and nitrogen oxides into less harmful gases. The muffler reduces noise, and the converter slightly restricts exhaust flow rather than adding power.

6. 6.

   Which saw is best for cutting curves and intricate shapes in wood?

   • A.

     Hacksaw

   • B.

     Crosscut saw

   • C.

     Coping saw

   • D.

     Rip saw

   Answer: C.

   A coping saw has a thin, narrow blade in a U-shaped frame that can follow tight curves. Crosscut and rip saws make straight cuts, and a hacksaw is for metal.

7. 7.

   Which tool is used to tighten a bolt to a specific, measured tightness?

   • A.

     Socket wrench

   • B.

     Torque wrench

   • C.

     Pipe wrench

   • D.

     Allen wrench

   Answer: B.

   A torque wrench clicks or reads out when the set torque is reached, preventing over- or under-tightening of parts like cylinder heads and lug nuts. A socket wrench turns the bolt but gives no measurement.

8. 8.

   Which saw is designed to cut metal?

   • A.

     Hacksaw

   • B.

     Rip saw

   • C.

     Coping saw

   • D.

     Backsaw

   Answer: A.

   A hacksaw has a fine-toothed, replaceable blade held under tension in a frame, made for cutting metal pipe, rod and bolts. Rip saws, coping saws and backsaws are woodworking saws.

9. 9.

   A hand plane is used to

   • A.

     bore holes in wood

   • B.

     shave thin layers from wood

   • C.

     cut threads in metal

   • D.

     clamp pieces together while glue dries

   Answer: B.

   A plane holds a blade at a fixed angle to remove thin shavings, flattening and smoothing wood. Drills and augers bore holes, taps cut threads, and clamps hold work.

10. 10.

    Which tool is used to make a small starting dent in metal so a drill bit does not wander?

    • A.

      Center punch

    • B.

      Scratch awl

    • C.

      Countersink

    • D.

      Drift punch

    Answer: A.

    A center punch is struck with a hammer to make a dimple that guides the drill bit. A scratch awl marks lines on wood, a countersink widens the top of a hole, and a drift punch drives out pins.