25 realistic Tank Vehicles practice questions for North Carolina 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 · Placards
What's the role of the tanker placard?
-
A.
To identify cargo for emergency responders
-
B.
To indicate the vehicle is heavy
-
C.
To indicate the vehicle is restricted
-
D.
To warn of slow speed
Correct answer: A.
Placards identify cargo, alerting first responders to the type of hazard.
Question 2 of 25 · Tank Types
What is "compartmented tanks"?
-
A.
Tanks split into multiple sections
-
B.
Tanks made for grain
-
C.
Tanks made for hazardous materials only
-
D.
Tanks with one large interior
Correct answer: A.
Compartmented tanks have multiple sections so different liquids can be carried separately.
Question 3 of 25 · Tank Types
What's a key difference between compartmented and smooth-bore tanks?
-
A.
Compartmented tanks reduce surge between sections
-
B.
Smooth-bore tanks have less surge
-
C.
They are the same in terms of surge
-
D.
Compartmented tanks are always larger
Correct answer: A.
Compartmented tanks reduce overall surge by limiting movement to each section.
Question 4 of 25 · Inspection
What's the importance of the tank shell's integrity?
-
A.
It contains the cargo and prevents leaks
-
B.
It supports the chassis
-
C.
It absorbs shock
-
D.
It connects to the brakes
Correct answer: A.
A sound tank shell prevents leaks and contains pressure from the cargo.
Question 5 of 25 · Vehicle Dynamics
Why must drivers be especially careful when starting and stopping a tanker?
-
A.
Surge can cause loss of control
-
B.
Engine torque is too high
-
C.
Brakes are weaker
-
D.
Steering is harder
Correct answer: A.
Surge during starts and stops can shove the vehicle and cause loss of control.
Question 6 of 25 · Vehicle Dynamics
What can cause a tanker to roll over?
-
A.
Sharp turns
-
B.
Sudden steering corrections
-
C.
Speed too high for road conditions
-
D.
All of the above
Correct answer: D.
All of these can cause rollovers; smooth, slow inputs reduce risk.
Question 7 of 25 · Loading
What is "outage" requirement for liquids that expand a lot?
-
A.
Larger outage required
-
B.
Less outage required
-
C.
No outage required
-
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 8 of 25 · Inspection
What's the importance of regular maintenance for tank vehicles?
-
A.
Prevents leaks
-
B.
Ensures safe operation
-
C.
Identifies problems before failures
-
D.
All of the above
Correct answer: D.
Routine maintenance prevents leaks, failures, and unsafe operation.
Question 9 of 25 · Tank Types
What is a "smooth bore" tank?
-
A.
A tank with internal baffles
-
B.
A tank without internal baffles or compartments
-
C.
A heated tank
-
D.
A two-compartment tank
Correct answer: B.
Smooth-bore tanks have no internal baffles, so liquid surge is unrestrained.
Question 10 of 25 · Backing
What should a driver do before backing a tanker?
-
A.
Check the path with a helper
-
B.
Look behind the vehicle
-
C.
Walk around the vehicle to check clearances
-
D.
All of the above
Correct answer: D.
Use a helper, walk-around, and check the path before backing.
Question 11 of 25 · Adverse Conditions
What's the safe way to handle a tanker in heavy wind?
-
A.
Slow down and grip steering firmly
-
B.
Speed up to maintain control
-
C.
Use the engine retarder
-
D.
Lock the brakes
Correct answer: A.
High winds destabilize tankers; slow down and steer firmly.
Question 12 of 25 · Vehicle Dynamics
How can drivers prevent tanker rollover?
-
A.
Reduce speed in curves and ramps
-
B.
Avoid sudden steering
-
C.
Maintain proper load and securement
-
D.
All of the above
Correct answer: D.
Slow speed, smooth steering, and proper loading all help prevent rollovers.
Question 13 of 25 · Tank Types
What is the purpose of internal baffles?
-
A.
To reduce side-to-side surge
-
B.
To reduce forward and back surge
-
C.
To prevent leaks
-
D.
To increase tank size
Correct answer: B.
Baffles reduce front-to-back surge but do not stop side-to-side surge.
Question 14 of 25 · Inspection
Why must drivers check the discharge valve before driving?
-
A.
To verify it is closed and not leaking
-
B.
To allow ventilation
-
C.
To start the engine
-
D.
To engage the brakes
Correct answer: A.
Discharge valves must be closed and leak-free before driving.
Question 15 of 25 · Loading
Why must tanker drivers be careful when refueling?
-
A.
Risk of fire from spills
-
B.
Risk of cargo contamination
-
C.
Risk of overloading
-
D.
Both A and B
Correct answer: D.
Spills can ignite and cargo can be contaminated by fuel.
Question 16 of 25 · Speed Management
When should tank drivers especially reduce speed?
-
A.
On wet or slippery roads
-
B.
On curves
-
C.
On ramps
-
D.
All of the above
Correct answer: D.
Slow down on wet roads, curves, and ramps — all increase rollover risk.
Question 17 of 25 · Vehicle Dynamics
What's a key safety feature in modern tankers?
-
A.
Automatic emergency braking
-
B.
Stability control systems
-
C.
Reinforced tank shells
-
D.
All of the above
Correct answer: D.
Modern tankers often combine ABS, stability control, and reinforced shells for safety.
Question 18 of 25 · Speed Management
What should you do when going around curves with a tanker?
-
A.
Slow down well below the posted speed
-
B.
Drive at the posted speed limit
-
C.
Use the engine retarder
-
D.
Lock the brakes
Correct answer: A.
Take curves at speeds well below the posted limit to avoid rollovers.
Question 19 of 25 · Vehicle Dynamics
How do drivers minimize side-to-side surge?
-
A.
Avoid abrupt lane changes and turns
-
B.
Take turns wide and slow
-
C.
Use partial loads
-
D.
Both A and B
Correct answer: D.
Smooth, slow inputs and wide turns help reduce side-to-side surge.
Question 20 of 25 · Vehicle Dynamics
Why is liquid surge dangerous?
-
A.
It can cause the truck to roll over
-
B.
It can push the truck in the direction the wave moves
-
C.
It can affect handling and braking
-
D.
All of the above
Correct answer: D.
Surge can roll, push, and disrupt braking — drivers must anticipate it.
Question 21 of 25 · Vehicle Dynamics
Why is the high center of gravity dangerous?
-
A.
It increases rollover risk
-
B.
It makes the vehicle more aerodynamic
-
C.
It improves traction
-
D.
It reduces braking force
Correct answer: A.
A high CG raises rollover risk, especially in turns or sudden maneuvers.
Question 22 of 25 · Mountain Driving
What's the proper way to handle a tanker on a steep downgrade?
-
A.
Use lower gears and engine braking with intermittent service brake
-
B.
Coast in neutral
-
C.
Brake hard the whole way
-
D.
Use the parking brake
Correct answer: A.
Lower gears and engine braking; use service brakes intermittently to avoid overheating.
Question 23 of 25 · Inspection
When checking tanks during pre-trip, what should be inspected?
-
A.
Tank shell for cracks or corrosion
-
B.
Manhole cover and seals
-
C.
Discharge valves
-
D.
All of the above
Correct answer: D.
Inspect the shell, seals, valves, and other tank components every pre-trip.
Question 24 of 25 · Vehicle Dynamics
Why are tank vehicles often top-heavy?
-
A.
The cargo is dense
-
B.
The cargo's liquid weight rises with the tank shape
-
C.
They have raised cargo platforms
-
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 25 of 25 · Loading
How can drivers tell if a tank is properly loaded?
-
A.
Check that all compartments are filled within outage limits
-
B.
Check the weight distribution
-
C.
Confirm valves are closed
-
D.
All of the above
Correct answer: D.
Verify outage, weight distribution, and closed valves before moving.
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 North Carolina Division of Motor Vehicles administers this knowledge test as part of its commercial driver license program. To earn the Tank Endorsement (N) on your North Carolina CDL, you need to score at least 16 out of 20 on the official version.
Topics covered on this practice test
- Vehicle Dynamics: 8 questions
- Tank Types: 4 questions
- Inspection: 4 questions
- Loading: 3 questions
- Speed Management: 2 questions
- Placards: 1 question
- Backing: 1 question
- Adverse Conditions: 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 North Carolina 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.