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Mississippi Tank Vehicle CDL Practice Test

Below are 25 exam-style questions for the Mississippi Tank Vehicle CDL knowledge test, modeled on the FMCSA-aligned content used by the Mississippi Department of Public Safety. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.

Heads up: this is a study tool, not a graded exam. Cover the answer with your hand or a sheet of paper for an honest practice run, then re-read the explanations for any questions you missed. Aim for 22 out of 25 or better, three times in a row, before scheduling the real exam.
Question 1 of 25
When operating in heavy traffic with a tanker:
  • A Cut between cars
  • B Drive at posted speed
  • C Tailgate to keep position
  • D Maintain extra following distance to allow gentle braking
Correct answer: D
Extra cushion ahead allows the gentle braking surge requires.
Question 2 of 25
When carrying flammable liquids, no smoking is allowed within:
  • A 25 feet of the vehicle
  • B 10 feet of the vehicle
  • C 100 feet
  • D Anywhere outside the cab
Correct answer: A
Federal rule prohibits smoking within 25 feet of a placarded flammable liquid vehicle.
Question 3 of 25
Bonding and grounding for flammable liquids is intended to:
  • A Prevent corrosion
  • B Reduce noise
  • C Improve fuel mileage
  • D Prevent static-electricity sparks during loading and unloading
Correct answer: D
Bonding equalizes electrical potential; grounding sends static to earth.
Question 4 of 25
Tanker drivers should be especially careful when:
  • A The tank is partially loaded and surge is highest
  • B All of the above
  • C On curves, ramps, and slick surfaces
  • D Stopping or starting in traffic
Correct answer: B
All three situations magnify tanker handling challenges.
Question 5 of 25
A tanker on a curve should be driven:
  • A In neutral
  • B Above posted speed
  • C At posted speed
  • D At least 5 mph below the posted curve speed when loaded
Correct answer: D
Posted curve speeds are calibrated for cars; tankers should slow more.
Question 6 of 25
When you brake a tanker, the surge can:
  • A Push you forward after you stop
  • B Have no effect
  • C Improve traction
  • D Help you stop sooner
Correct answer: A
Forward surge after stopping is the classic tanker hazard.
Question 7 of 25
When you discover a leak in the tank during the trip:
  • A Continue to the destination
  • B Try to repair the leak yourself
  • C Drive faster
  • D Stop in a safe location, isolate the area, and notify the carrier and authorities
Correct answer: D
Leak procedures require stop, isolate, and notify.
Question 8 of 25
"Outage" in tanker operations means:
  • A Equipment failure
  • B The empty space left in a tank for product expansion
  • C A driver shortage
  • D A tank leak
Correct answer: B
Outage is the unfilled space allowed for liquid expansion in heat.
Question 9 of 25
A tanker driver should never:
  • A Drive over the maximum allowable speed for the load
  • B All of the above
  • C Skip a pre-trip inspection
  • D Disregard outage requirements
Correct answer: B
All three are violations of safe tanker operation.
Question 10 of 25
When adding chemicals to a tanker, the driver should:
  • A Skip the safety check
  • B Verify product compatibility and follow safety procedures
  • C Allow the receiver to add chemicals
  • D Mix freely
Correct answer: B
Compatibility prevents reactions and contamination.
Question 11 of 25
In emergency response, a tanker driver should:
  • A Rely on memory only
  • B Wait for the carrier to instruct
  • C Refer to the ERG and shipping papers for product-specific guidance
  • D Open all vents
Correct answer: C
ERG and shipping papers give the immediate emergency procedure.
Question 12 of 25
A tanker on a slippery road should:
  • A Use the parking brake
  • B Brake earlier and more gently than normal
  • C Maintain speed
  • D Brake harder to make up for traction loss
Correct answer: B
Reduced traction plus surge requires extra care; brake gently and earlier.
Question 13 of 25
A "wet line" on a tanker is:
  • A A frozen pipe
  • B A fuel line
  • C An air-brake line
  • D A pipe that contains residual liquid product
Correct answer: D
Wet lines contain liquid that can leak from valves; check during inspection.
Question 14 of 25
When a tanker is in a long downgrade and brakes start to fade:
  • A Maintain pressure on the brakes
  • B Increase speed
  • C Coast in neutral
  • D Use the escape ramp
Correct answer: D
Escape ramps are the engineered solution for runaway tankers.
Question 15 of 25
When parking a tanker, you should:
  • A Set only the tractor parking brake
  • B Set both tractor and trailer parking brakes and chock if necessary
  • C Use the trailer hand valve
  • D Leave brakes off
Correct answer: B
Full parking-brake set plus chocks where needed for tanker stability.
Question 16 of 25
A tank vehicle's rollover risk is:
  • A Lower than a flatbed
  • B Eliminated by ABS
  • C Always present, especially with a high center of gravity and liquid surge
  • D Only an issue when empty
Correct answer: C
High CG and surge create persistent rollover risk; ABS does not eliminate it.
Question 17 of 25
When unloading a tanker, you should:
  • A Drive while unloading
  • B Open vents only after pressure is equalized
  • C Skip the venting
  • D Open vents while pressure is high
Correct answer: B
Equalize pressure first to prevent splash, vapor release, and damage.
Question 18 of 25
A tanker driver who must back the truck should:
  • A Use only mirrors
  • B GOAL — Get Out And Look — and use a spotter when possible
  • C Back at full speed
  • D Skip the visual check
Correct answer: B
Backing risk is high; visual check and spotter are key.
Question 19 of 25
A tanker on a long downhill with brake fade should:
  • A Coast in neutral
  • B Increase speed to clear the descent
  • C Use the parking brake harder
  • D Look for an escape ramp
Correct answer: D
Escape ramps are designed for runaway trucks, including tankers.
Question 20 of 25
A tanker is more sensitive to wind because:
  • A Its high center of gravity and large surface area increase wind effects
  • B It is heavier
  • C It uses air brakes
  • D It is shorter
Correct answer: A
Wind can push and tip a tanker; reduce speed in heavy crosswinds.
Question 21 of 25
When entering a freeway off-ramp in a tanker:
  • A Maintain freeway speed
  • B Brake within the curve
  • C Use the parking brake
  • D Reduce speed before the ramp and watch for tightening curves
Correct answer: D
Off-ramps tighten and surprise unprepared tanker drivers.
Question 22 of 25
After about 25 miles, a tanker driver should:
  • A Drive without checking
  • B Speed up
  • C Take a break only
  • D Pull over and re-check the load and securement
Correct answer: D
Heat, vibration, and load shift can loosen what was tight at the yard.
Question 23 of 25
When loading a tank, you should:
  • A Overfill if running low on time
  • B Leave room for product expansion (outage)
  • C Skip the outage if the product is cold
  • D Fill the tank completely
Correct answer: B
Outage prevents pressure damage and spills as product warms.
Question 24 of 25
A tanker driver should plan trips to:
  • A Avoid all freeways
  • B Take the shortest route regardless of grade
  • C Avoid steep grades and sharp curves where possible
  • D Use the parking brake on grades
Correct answer: C
Route planning reduces handling demands on the tanker.
Question 25 of 25
After loading, a tanker driver must:
  • A Check fittings and covers for leaks before leaving the loading site
  • B Skip the inspection
  • C Allow the shipper to drive
  • D Drive immediately
Correct answer: A
Leak checks at the loading site catch problems before they hit the road.

Study tips for the Mississippi Tank Vehicle exam

The Tank Vehicle portion of the Mississippi CDL exam is graded out of the bank of questions the Mississippi Department of Public Safety draws from each year. While the exact bank is not published, every question is sourced from the Tank Vehicle chapter of the Mississippi CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.

Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official Mississippi handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.

Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about Tank Vehicle.

Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The Mississippi Department of Public Safety will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.

Finally, keep your General Knowledge fundamentals sharp even when you're focused on the Tank Vehicle exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh Mississippi General Knowledge practice test before scheduling the real exam.

Next steps

Missed more than four questions? Re-read the Tank Vehicle study guide and the matching chapter in the official Mississippi CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local Mississippi Department of Public Safety office.

Already comfortable with this endorsement? Drill another: MS General Knowledge · MS Air Brakes · MS Combination Vehicles · MS Hazardous Materials · MS Passenger · MS School Bus · MS Doubles / Triples

New to the CDL process in Mississippi? Read How to apply for a CDL in Mississippi for the document checklist and step-by-step timeline.