25 realistic Tank Vehicles practice questions for Maine CDL applicants. Required for: Vehicles with liquid or gaseous tanks ≥1,000 gallons. Official test: 20 questions, 16 correct to pass.
Question 1 of 25 · Adverse Conditions
What's the best practice for starting on slippery roads with a tanker?
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A.
Accelerate slowly to avoid wheel spin
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B.
Accelerate quickly
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C.
Use the lowest gear and slip clutch
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D.
Use parking brake
Correct answer: A.
Smooth, slow acceleration avoids spinning the drive tires.
Question 2 of 25 · Inspection
What's the importance of the tank shell's integrity?
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A.
It contains the cargo and prevents leaks
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B.
It supports the chassis
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C.
It absorbs shock
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D.
It connects to the brakes
Correct answer: A.
A sound tank shell prevents leaks and contains pressure from the cargo.
Question 3 of 25 · Inspection
What is the proper way to inspect a tank before driving?
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A.
Check valves, manhole, and tank shell for leaks and damage
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B.
Just check the tires
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C.
Only inspect the engine
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D.
Skip inspection if you're in a hurry
Correct answer: A.
Inspect valves, manhole, shell, hoses, and other tank components every pre-trip.
Question 4 of 25 · Emergencies
What action should a driver take if a tank starts to leak?
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A.
Stop immediately in a safe area and report the leak
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B.
Continue to destination
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C.
Try to close the leak
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D.
Drive faster
Correct answer: A.
Stop in a safe area, secure the area, and notify the carrier and emergency services.
Question 5 of 25 · Placards
Why are tankers required to have specific markings?
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A.
To identify the cargo and any hazards
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B.
To make them more visible
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C.
For tax purposes
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D.
For insurance only
Correct answer: A.
Markings identify cargo and any hazards for emergency responders and others.
Question 6 of 25 · Loading
What is a vapor recovery system?
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A.
A way to recover heat
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B.
A system to recover vapors during loading and unloading to reduce emissions
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C.
An air brake component
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D.
A backup pump
Correct answer: B.
Vapor recovery captures vapors during transfer to limit emissions.
Question 7 of 25 · Placards
What's the role of the tanker placard?
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A.
To identify cargo for emergency responders
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B.
To indicate the vehicle is heavy
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C.
To indicate the vehicle is restricted
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D.
To warn of slow speed
Correct answer: A.
Placards identify cargo, alerting first responders to the type of hazard.
Question 8 of 25 · Loading
What is "outage" in tank operations?
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A.
Lost electricity
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B.
Empty space allowed in a tank for liquid to expand
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C.
Tank failure
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D.
Loss of brake pressure
Correct answer: B.
Liquids expand with heat. Outage is the empty space left for that expansion.
Question 9 of 25 · Inspection
How can drivers detect a tank leak?
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A.
Visual inspection during pre-trip and en-route stops
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B.
Smell of the cargo
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C.
Sound of escaping fluid
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D.
All of the above
Correct answer: D.
Sight, smell, and sound can all help detect leaks. Inspect at every stop.
Question 10 of 25 · Adverse Conditions
What's the safe way to handle a tanker on icy roads?
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A.
Slow down and increase following distance
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B.
Use chains if required
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C.
Avoid sudden braking and steering
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D.
All of the above
Correct answer: D.
Reduced speed, chains where required, and smooth inputs reduce risk on ice.
Question 11 of 25 · Tank Types
What is the purpose of internal baffles?
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A.
To reduce side-to-side surge
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B.
To reduce forward and back surge
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C.
To prevent leaks
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D.
To increase tank size
Correct answer: B.
Baffles reduce front-to-back surge but do not stop side-to-side surge.
Question 12 of 25 · Vehicle Dynamics
Why must drivers be especially careful when starting and stopping a tanker?
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A.
Surge can cause loss of control
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B.
Engine torque is too high
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C.
Brakes are weaker
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D.
Steering is harder
Correct answer: A.
Surge during starts and stops can shove the vehicle and cause loss of control.
Question 13 of 25 · Vehicle Dynamics
Why is the high center of gravity dangerous?
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A.
It increases rollover risk
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B.
It makes the vehicle more aerodynamic
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C.
It improves traction
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D.
It reduces braking force
Correct answer: A.
A high CG raises rollover risk, especially in turns or sudden maneuvers.
Question 14 of 25 · Adverse Conditions
What's the safe way to handle a tanker in heavy wind?
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A.
Slow down and grip steering firmly
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B.
Speed up to maintain control
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C.
Use the engine retarder
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D.
Lock the brakes
Correct answer: A.
High winds destabilize tankers; slow down and steer firmly.
Question 15 of 25 · Emergency Maneuvers
What's the best approach to handling a flat tire on a tanker?
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A.
Pull over safely and replace the tire or call for help
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B.
Continue driving
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C.
Drive faster to make it to the next exit
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D.
Stop in the middle of the road
Correct answer: A.
Stop safely and address the flat — driving on it can lead to bigger problems.
Question 16 of 25 · Vehicle Dynamics
Why are tank vehicles often top-heavy?
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A.
The cargo is dense
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B.
The cargo's liquid weight rises with the tank shape
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C.
They have raised cargo platforms
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D.
The center of gravity is high due to liquid load
Correct answer: D.
Tank vehicles tend to have a high center of gravity, making them prone to rollover.
Question 17 of 25 · Loading
What's the consequence of overloading a tank?
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A.
Increased wear on tires and brakes
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B.
Possible tank rupture
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C.
Illegal weight violations
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D.
All of the above
Correct answer: D.
Overloading causes wear, legal trouble, and danger of tank failure.
Question 18 of 25 · Speed Management
What should you do when going around curves with a tanker?
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A.
Slow down well below the posted speed
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B.
Drive at the posted speed limit
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C.
Use the engine retarder
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D.
Lock the brakes
Correct answer: A.
Take curves at speeds well below the posted limit to avoid rollovers.
Question 19 of 25 · Loading
What is "outage" requirement for liquids that expand a lot?
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A.
Larger outage required
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B.
Less outage required
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C.
No outage required
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D.
Outage doesn't depend on the liquid
Correct answer: A.
Liquids that expand more (e.g., LPG) require greater outage in the tank.
Question 20 of 25 · Inspection
When checking tanks during pre-trip, what should be inspected?
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A.
Tank shell for cracks or corrosion
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B.
Manhole cover and seals
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C.
Discharge valves
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D.
All of the above
Correct answer: D.
Inspect the shell, seals, valves, and other tank components every pre-trip.
Question 21 of 25 · Tank Types
What's a "high-volume" tank?
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A.
A tank with capacity greater than typical
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B.
A tank with high pressure
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C.
A tank with multiple compartments
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D.
A tank with a smooth interior
Correct answer: A.
High-volume tanks carry more than typical loads and are subject to special rules.
Question 22 of 25 · Mountain Driving
What's the proper way to handle a tanker on a steep downgrade?
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A.
Use lower gears and engine braking with intermittent service brake
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B.
Coast in neutral
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C.
Brake hard the whole way
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D.
Use the parking brake
Correct answer: A.
Lower gears and engine braking; use service brakes intermittently to avoid overheating.
Question 23 of 25 · Loading
How can drivers tell if a tank is properly loaded?
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A.
Check that all compartments are filled within outage limits
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B.
Check the weight distribution
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C.
Confirm valves are closed
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D.
All of the above
Correct answer: D.
Verify outage, weight distribution, and closed valves before moving.
Question 24 of 25 · Vehicle Dynamics
When is it most dangerous to brake suddenly in a tanker?
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A.
When tank is partially full
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B.
When tank is fully loaded
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C.
When tank is empty
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D.
When tank is heated
Correct answer: A.
Partial loads create the most surge during sudden braking.
Question 25 of 25 · Vehicle Dynamics
How does liquid weight affect handling?
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A.
It changes the center of gravity
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B.
It affects acceleration
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C.
It affects braking
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D.
All of the above
Correct answer: D.
Liquid loads alter CG and dramatically affect acceleration and braking.
About the Tank Vehicles Test
The Tank Vehicles test covers inspecting tank vehicles, driving tank vehicles, surge and liquid movement, baffled and unbaffled tanks, outage, and safe driving rules unique to large liquid loads. Tank vehicles handle very differently from dry-freight vehicles because liquid surge can shove the vehicle in the direction the wave moves.
The Maine Bureau of Motor Vehicles administers this knowledge test as part of its commercial driver license program. To earn the Tank Endorsement (N) on your Maine CDL, you need to score at least 16 out of 20 on the official version.
Topics covered on this practice test
- Loading: 5 questions
- Vehicle Dynamics: 5 questions
- Inspection: 4 questions
- Adverse Conditions: 3 questions
- Placards: 2 questions
- Tank Types: 2 questions
- Emergencies: 1 question
- Emergency Maneuvers: 1 question
- Speed Management: 1 question
- Mountain Driving: 1 question
How to use this practice test
- Read each question carefully. CDL questions are written precisely — small wording differences matter.
- Click "Show Answers & Explanations" only after answering every question. Don't peek mid-test.
- Read the explanation for every question, even ones you got right. The reasoning is more important than the answer.
- Repeat the test until you score 100%. The questions are deterministic per state, so you can track your improvement over multiple sessions.
- Move on to the other endorsement tests for Maine until you're ready for the official exam.
Tips specific to the Tank Vehicles test
Tank vehicle questions focus on liquid surge, outage, smooth-bore versus baffled tanks, high center of gravity, and the special braking and turning techniques required to keep a partially-loaded tank under control. Expect several questions about leak response and load distribution.