25 realistic Tank Vehicles practice questions for Oregon 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 · Vehicle Dynamics
How do drivers minimize side-to-side surge?
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A.
Avoid abrupt lane changes and turns
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B.
Take turns wide and slow
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C.
Use partial loads
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D.
Both A and B
Correct answer: D.
Smooth, slow inputs and wide turns help reduce side-to-side surge.
Question 2 of 25 · Loading
Why is it important not to overload tank vehicles?
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A.
Overloading exceeds weight limits
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B.
It increases risk of tank rupture
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C.
It changes vehicle handling
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D.
All of the above
Correct answer: D.
Overloading is illegal and unsafe; it changes handling and stresses the tank.
Question 3 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 4 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 5 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 6 of 25 · Speed Management
When should tank drivers especially reduce speed?
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A.
On wet or slippery roads
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B.
On curves
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C.
On ramps
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D.
All of the above
Correct answer: D.
Slow down on wet roads, curves, and ramps — all increase rollover risk.
Question 7 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 8 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 9 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 10 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 11 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 12 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 13 of 25 · Tank Types
What's a key difference between compartmented and smooth-bore tanks?
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A.
Compartmented tanks reduce surge between sections
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B.
Smooth-bore tanks have less surge
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C.
They are the same in terms of surge
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D.
Compartmented tanks are always larger
Correct answer: A.
Compartmented tanks reduce overall surge by limiting movement to each section.
Question 14 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 15 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 16 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 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 · 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 19 of 25 · Mountain Driving
How do drivers control speed on downgrades with tankers?
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A.
Use lower gears and engine braking
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B.
Use service brakes only
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C.
Coast with no brakes
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D.
Use parking brake
Correct answer: A.
Use proper low gears and engine braking; service brakes only intermittently.
Question 20 of 25 · Speed Management
What is the leading cause of tanker rollover?
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A.
Driver error such as speed too high for curves
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B.
Mechanical failure
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C.
Weather only
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D.
Tire blowouts
Correct answer: A.
Speed too high for conditions, especially in curves, is the leading rollover cause.
Question 21 of 25 · Inspection
Why must drivers check the discharge valve before driving?
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A.
To verify it is closed and not leaking
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B.
To allow ventilation
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C.
To start the engine
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D.
To engage the brakes
Correct answer: A.
Discharge valves must be closed and leak-free before driving.
Question 22 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 23 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 24 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 25 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.
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 Oregon Driver and Motor Vehicle Services administers this knowledge test as part of its commercial driver license program. To earn the Tank Endorsement (N) on your Oregon CDL, you need to score at least 16 out of 20 on the official version.
Topics covered on this practice test
- Vehicle Dynamics: 5 questions
- Loading: 3 questions
- Tank Types: 3 questions
- Adverse Conditions: 2 questions
- Speed Management: 2 questions
- Placards: 2 questions
- Inspection: 2 questions
- Emergencies: 1 question
- Backing: 1 question
- CDL Rules: 1 question
- Parking: 1 question
- Mountain Driving: 1 question
- Operation: 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 Oregon 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.