25 realistic Tank Vehicles practice questions for Wisconsin 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 · Emergencies
What action should a driver take if a tank starts to leak?
-
A.
Stop immediately in a safe area and report the leak
-
B.
Continue to destination
-
C.
Try to close the leak
-
D.
Drive faster
Correct answer: A.
Stop in a safe area, secure the area, and notify the carrier and emergency services.
Question 2 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 3 of 25 · Vehicle Dynamics
When is liquid surge greatest?
-
A.
When tanks are full
-
B.
When tanks are partially full
-
C.
When tanks are empty
-
D.
When tanks are heated
Correct answer: B.
Surge is greatest when tanks are partially full and the liquid can move freely.
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 · 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.
Question 6 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 7 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 8 of 25 · Parking
What's the safest place to park a tank vehicle overnight?
-
A.
Designated truck parking areas away from buildings
-
B.
On the highway shoulder
-
C.
In residential areas
-
D.
Anywhere with lighting
Correct answer: A.
Use designated truck parking areas away from people and buildings.
Question 9 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 10 of 25 · Adverse Conditions
What's the safe way to handle a tanker on icy roads?
-
A.
Slow down and increase following distance
-
B.
Use chains if required
-
C.
Avoid sudden braking and steering
-
D.
All of the above
Correct answer: D.
Reduced speed, chains where required, and smooth inputs reduce risk on ice.
Question 11 of 25 · Operation
What's the recommended safe braking technique for tank trucks?
-
A.
Apply brakes gradually well before stopping
-
B.
Quick, hard braking
-
C.
Use the engine retarder primarily
-
D.
Brake at the last second
Correct answer: A.
Brake gradually and well in advance — sudden braking magnifies surge.
Question 12 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 13 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 14 of 25 · Loading
What is a vapor recovery system?
-
A.
A way to recover heat
-
B.
A system to recover vapors during loading and unloading to reduce emissions
-
C.
An air brake component
-
D.
A backup pump
Correct answer: B.
Vapor recovery captures vapors during transfer to limit emissions.
Question 15 of 25 · Loading
When loading tanks, what must drivers consider?
-
A.
Outage requirements for the liquid
-
B.
Weight distribution between compartments
-
C.
Surge potential
-
D.
All of the above
Correct answer: D.
Outage, weight distribution, and surge management all matter when loading tanks.
Question 16 of 25 · Vehicle Dynamics
When is it most dangerous to brake suddenly in a tanker?
-
A.
When tank is partially full
-
B.
When tank is fully loaded
-
C.
When tank is empty
-
D.
When tank is heated
Correct answer: A.
Partial loads create the most surge during sudden braking.
Question 17 of 25 · HazMat Driving
Why is "no smoking" enforced near tankers?
-
A.
Risk of fire and explosion from cargo vapors
-
B.
Cleanliness
-
C.
Tradition
-
D.
OSHA rules only
Correct answer: A.
Vapors can ignite or explode; smoking is prohibited near tankers.
Question 18 of 25 · Tank Types
What's a "high-volume" tank?
-
A.
A tank with capacity greater than typical
-
B.
A tank with high pressure
-
C.
A tank with multiple compartments
-
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 19 of 25 · Mountain Driving
How do drivers control speed on downgrades with tankers?
-
A.
Use lower gears and engine braking
-
B.
Use service brakes only
-
C.
Coast with no brakes
-
D.
Use parking brake
Correct answer: A.
Use proper low gears and engine braking; service brakes only intermittently.
Question 20 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 21 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 22 of 25 · Vehicle Dynamics
How does liquid weight affect handling?
-
A.
It changes the center of gravity
-
B.
It affects acceleration
-
C.
It affects braking
-
D.
All of the above
Correct answer: D.
Liquid loads alter CG and dramatically affect acceleration and braking.
Question 23 of 25 · Adverse Conditions
What's the best practice for starting on slippery roads with a tanker?
-
A.
Accelerate slowly to avoid wheel spin
-
B.
Accelerate quickly
-
C.
Use the lowest gear and slip clutch
-
D.
Use parking brake
Correct answer: A.
Smooth, slow acceleration avoids spinning the drive tires.
Question 24 of 25 · Inspection
How can drivers detect a tank leak?
-
A.
Visual inspection during pre-trip and en-route stops
-
B.
Smell of the cargo
-
C.
Sound of escaping fluid
-
D.
All of the above
Correct answer: D.
Sight, smell, and sound can all help detect leaks. Inspect at every stop.
Question 25 of 25 · Emergency Maneuvers
What's the best approach to handling a flat tire on a tanker?
-
A.
Pull over safely and replace the tire or call for help
-
B.
Continue driving
-
C.
Drive faster to make it to the next exit
-
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.
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 Wisconsin Division of Motor Vehicles administers this knowledge test as part of its commercial driver license program. To earn the Tank Endorsement (N) on your Wisconsin CDL, you need to score at least 16 out of 20 on the official version.
Topics covered on this practice test
- Vehicle Dynamics: 4 questions
- Loading: 4 questions
- Inspection: 3 questions
- Tank Types: 3 questions
- Adverse Conditions: 2 questions
- Emergencies: 1 question
- Backing: 1 question
- Parking: 1 question
- Operation: 1 question
- Speed Management: 1 question
- HazMat Driving: 1 question
- Mountain Driving: 1 question
- Placards: 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 Wisconsin 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.