25 realistic Tank Vehicles practice questions for Delaware 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 · 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 2 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 3 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 4 of 25 · Operation
What's the recommended safe braking technique for tank trucks?
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A.
Apply brakes gradually well before stopping
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B.
Quick, hard braking
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C.
Use the engine retarder primarily
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D.
Brake at the last second
Correct answer: A.
Brake gradually and well in advance — sudden braking magnifies surge.
Question 5 of 25 · Vehicle Dynamics
What's a key safety feature in modern tankers?
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A.
Automatic emergency braking
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B.
Stability control systems
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C.
Reinforced tank shells
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D.
All of the above
Correct answer: D.
Modern tankers often combine ABS, stability control, and reinforced shells for safety.
Question 6 of 25 · Vehicle Dynamics
When is liquid surge greatest?
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A.
When tanks are full
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B.
When tanks are partially full
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C.
When tanks are empty
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D.
When tanks are heated
Correct answer: B.
Surge is greatest when tanks are partially full and the liquid can move freely.
Question 7 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 8 of 25 · Inspection
What's the importance of regular maintenance for tank vehicles?
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A.
Prevents leaks
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B.
Ensures safe operation
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C.
Identifies problems before failures
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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?
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A.
A tank with internal baffles
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B.
A tank without internal baffles or compartments
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C.
A heated tank
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D.
A two-compartment tank
Correct answer: B.
Smooth-bore tanks have no internal baffles, so liquid surge is unrestrained.
Question 10 of 25 · Vehicle Dynamics
What are some hazards of driving smooth-bore tankers?
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A.
Side-to-side and forward-and-back surge
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B.
High center of gravity
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C.
Difficult handling on curves
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D.
All of the above
Correct answer: D.
Smooth-bore tanks are especially prone to surge, rollover, and difficult handling.
Question 11 of 25 · Backing
What should a driver do before backing a tanker?
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A.
Check the path with a helper
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B.
Look behind the vehicle
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C.
Walk around the vehicle to check clearances
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D.
All of the above
Correct answer: D.
Use a helper, walk-around, and check the path before backing.
Question 12 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.
Question 13 of 25 · Emergency Equipment
What equipment must be on a HazMat tank vehicle?
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A.
Emergency response equipment
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B.
Spill kits as required
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C.
Communication devices
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D.
All of the above
Correct answer: D.
Carry spill response gear, communication, and any other required equipment.
Question 14 of 25 · Loading
Why must tanker drivers be careful when refueling?
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A.
Risk of fire from spills
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B.
Risk of cargo contamination
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C.
Risk of overloading
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D.
Both A and B
Correct answer: D.
Spills can ignite and cargo can be contaminated by fuel.
Question 15 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 16 of 25 · Vehicle Dynamics
What can drivers do to control surge?
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A.
Brake gradually well before stopping
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B.
Accelerate gradually
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C.
Allow extra following distance
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D.
All of the above
Correct answer: D.
Smooth braking and acceleration, plus extra space, all help control surge.
Question 17 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 18 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 19 of 25 · CDL Rules
How are tanker drivers trained for hazardous cargo?
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A.
Same as regular drivers
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B.
They receive specialized training and may need HazMat endorsement
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C.
No specific training required
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D.
They are trained by the shipper
Correct answer: B.
Hazardous tankers require additional training and often a HazMat endorsement.
Question 20 of 25 · Parking
What's the safest place to park a tank vehicle overnight?
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A.
Designated truck parking areas away from buildings
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B.
On the highway shoulder
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C.
In residential areas
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D.
Anywhere with lighting
Correct answer: A.
Use designated truck parking areas away from people and buildings.
Question 21 of 25 · HazMat Driving
Why is "no smoking" enforced near tankers?
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A.
Risk of fire and explosion from cargo vapors
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B.
Cleanliness
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C.
Tradition
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D.
OSHA rules only
Correct answer: A.
Vapors can ignite or explode; smoking is prohibited near tankers.
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 · 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 24 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 25 of 25 · Loading
When loading tanks, what must drivers consider?
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A.
Outage requirements for the liquid
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B.
Weight distribution between compartments
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C.
Surge potential
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D.
All of the above
Correct answer: D.
Outage, weight distribution, and surge management all matter when loading tanks.
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 Delaware Division of Motor Vehicles administers this knowledge test as part of its commercial driver license program. To earn the Tank Endorsement (N) on your Delaware CDL, you need to score at least 16 out of 20 on the official version.
Topics covered on this practice test
- Vehicle Dynamics: 7 questions
- Loading: 5 questions
- Inspection: 3 questions
- Operation: 1 question
- Adverse Conditions: 1 question
- Tank Types: 1 question
- Backing: 1 question
- Emergency Equipment: 1 question
- CDL Rules: 1 question
- Parking: 1 question
- HazMat Driving: 1 question
- Mountain Driving: 1 question
- Emergency Maneuvers: 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 Delaware 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.