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TX · N Endorsement

Texas Tank Vehicle CDL Practice Test

Below are 25 exam-style questions for the Texas Tank Vehicle CDL knowledge test, modeled on the FMCSA-aligned content used by the Texas 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
A tanker that is partially loaded:
  • A Has less surge than a full tank
  • B Has more surge than a full or empty tank
  • C Has the same surge
  • D Has no surge
Correct answer: B
Partial loads have the most room for the liquid to slosh.
Question 2 of 25
Tanker drivers should be especially careful when:
  • A On curves, ramps, and slick surfaces
  • B All of the above
  • C Stopping or starting in traffic
  • D The tank is partially loaded and surge is highest
Correct answer: B
All three situations magnify tanker handling challenges.
Question 3 of 25
A vapor-recovery system on a tanker:
  • A Reduces engine noise
  • B Improves fuel mileage
  • C Captures vapors during loading and unloading to reduce emissions
  • D Operates the brakes
Correct answer: C
Vapor recovery is required by environmental rules at many facilities.
Question 4 of 25
Lane changes in a tanker should be:
  • A Without signaling
  • B Smooth and gradual to minimize side-to-side surge
  • C Sharp and quick
  • D At any speed
Correct answer: B
Smooth maneuvers reduce surge that could affect handling.
Question 5 of 25
When unloading a tanker, you should:
  • A Open vents while pressure is high
  • B Drive while unloading
  • C Skip the venting
  • D Open vents only after pressure is equalized
Correct answer: D
Equalize pressure first to prevent splash, vapor release, and damage.
Question 6 of 25
After loading, a tanker driver must:
  • A Skip the inspection
  • B Drive immediately
  • C Allow the shipper to drive
  • D Check fittings and covers for leaks before leaving the loading site
Correct answer: D
Leak checks at the loading site catch problems before they hit the road.
Question 7 of 25
When adding chemicals to a tanker, the driver should:
  • A Mix freely
  • B Skip the safety check
  • C Verify product compatibility and follow safety procedures
  • D Allow the receiver to add chemicals
Correct answer: C
Compatibility prevents reactions and contamination.
Question 8 of 25
A tanker driver loading at a self-serve facility should:
  • A Allow another driver to load for them
  • B Begin loading without checking
  • C Follow site procedures and verify equipment before loading
  • D Skip the site procedures
Correct answer: C
Site procedures are designed to prevent spills and ensure safe loading.
Question 9 of 25
When loading a smooth-bore tank, the driver should:
  • A Be especially careful with starts and stops because surge will be severe
  • B Drive normally
  • C Skip the brake check
  • D Use only the parking brake
Correct answer: A
Smooth-bore tankers require gentle braking and acceleration to control surge.
Question 10 of 25
A tanker on a downgrade should:
  • A Increase speed
  • B Coast in neutral
  • C Be in low gear and use steady moderate brake application
  • D Use parking brake intermittently
Correct answer: C
Standard heavy-vehicle downgrade rule plus extra concern for surge.
Question 11 of 25
A driver loading a tanker with a flammable liquid must:
  • A Bond only after the loading is complete
  • B Disconnect the bonding mid-loading
  • C Bond and ground before opening the manhole
  • D Skip the bonding if the load is small
Correct answer: C
Bonding before opening prevents static-spark ignition.
Question 12 of 25
A tanker that is leaking should:
  • A Allow product to leak until empty
  • B Drive faster to limit the spill
  • C Stop, isolate the area, and notify emergency services and the carrier
  • D Continue to the destination
Correct answer: C
Leak management requires immediate stop and proper notification.
Question 13 of 25
When you stop quickly in a tanker, you should:
  • A Release the wheel
  • B Apply the parking brake immediately
  • C Hold the steering wheel firmly because the load may push you forward
  • D Disengage the clutch
Correct answer: C
Surge forces require firm steering control during and after the stop.
Question 14 of 25
When you discover a leak in the tank during the trip:
  • A Stop in a safe location, isolate the area, and notify the carrier and authorities
  • B Continue to the destination
  • C Try to repair the leak yourself
  • D Drive faster
Correct answer: A
Leak procedures require stop, isolate, and notify.
Question 15 of 25
When a tank is unbaffled (smooth-bore), the driver should:
  • A Drive normally
  • B Use only the parking brake to slow
  • C Allow extra following distance and brake earlier
  • D Disregard surge
Correct answer: C
Extra cushion ahead and earlier braking compensate for severe surge.
Question 16 of 25
Liquid surge in a tanker is most extreme in:
  • A Compartmented tanks
  • B Baffled tanks
  • C Smooth-bore (unbaffled) tanks
  • D Empty tanks
Correct answer: C
Smooth-bore tanks have no internal walls to slow the liquid; surge is severe and can push the truck after a stop.
Question 17 of 25
A "manhole cover" on a tanker:
  • A Is for the driver to enter the tank
  • B Is a road sign
  • C Is part of the brake system
  • D Provides access to the tank interior and must be sealed during transport
Correct answer: D
Manhole covers seal the tank; check sealing before driving.
Question 18 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 19 of 25
After unloading, the driver should:
  • A Drive away with vents open
  • B Skip the post-unload inspection
  • C Close vents and covers, secure equipment, and inspect for leaks before leaving
  • D Allow the receiver to close everything
Correct answer: C
Post-unload inspection ensures the tank is secured before transport.
Question 20 of 25
When parking a tanker, you should:
  • A Use the trailer hand valve
  • B Set only the tractor parking brake
  • C Leave brakes off
  • D Set both tractor and trailer parking brakes and chock if necessary
Correct answer: D
Full parking-brake set plus chocks where needed for tanker stability.
Question 21 of 25
The most common rollover scenario for tankers is:
  • A In stopped traffic
  • B On straight roads
  • C On a curve or off-ramp at speeds the driver thought were safe
  • D In low-speed maneuvers
Correct answer: C
Rollover happens at speeds the driver did not expect would matter; reduce more than you think.
Question 22 of 25
A tanker driver carrying hazardous materials must also have the:
  • A X endorsement (combination of H and N)
  • B L restriction
  • C H endorsement
  • D P endorsement
Correct answer: A
X endorsement combines Hazmat (H) and Tank (N) for hazmat liquid loads.
Question 23 of 25
A "cargo tank" on a vehicle is:
  • A A trailer-mounted tank
  • B A portable tank set on the vehicle
  • C All of the above can be a cargo tank
  • D Permanently mounted to the vehicle
Correct answer: C
Cargo tanks can be permanently mounted, portable, or trailer-mounted; specifications vary.
Question 24 of 25
A tanker driver should always:
  • A Use the trailer hand valve as a parking brake
  • B Drive at the posted speed regardless of conditions
  • C Be ready for surge during stops, starts, and turns
  • D Skip pre-trip checks of vents and covers
Correct answer: C
Anticipating surge is the constant tanker mindset.
Question 25 of 25
A high center of gravity in a tanker means:
  • A Faster acceleration
  • B No change in handling
  • C Easier handling
  • D Higher rollover risk
Correct answer: D
High CG combined with liquid surge dramatically increases rollover risk.

Study tips for the Texas Tank Vehicle exam

The Tank Vehicle portion of the Texas CDL exam is graded out of the bank of questions the Texas 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 Texas 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 Texas 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 Texas 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 Texas 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 Texas 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 Texas Department of Public Safety office.

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

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