Oklahoma Tank Vehicle CDL Practice Test
Below are 25 exam-style questions for the Oklahoma Tank Vehicle CDL knowledge test, modeled on the FMCSA-aligned content used by the Oklahoma 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.
- A Allow the receiver to close everything
- B Skip the post-unload inspection
- C Drive away with vents open
- D Close vents and covers, secure equipment, and inspect for leaks before leaving
- A A driver shortage
- B A tank leak
- C Equipment failure
- D The empty space left in a tank for product expansion
- A Easier handling
- B Faster acceleration
- C Higher rollover risk
- D No change in handling
- A Take the shortest route regardless of grade
- B Avoid steep grades and sharp curves where possible
- C Use the parking brake on grades
- D Avoid all freeways
- A 25 feet of the vehicle
- B 10 feet of the vehicle
- C Anywhere outside the cab
- D 100 feet
- A Disregard surge
- B Use the trailer hand valve as a parking brake
- C All of the above
- D Skip outage
- A Push you forward after you stop
- B Have no effect
- C Help you stop sooner
- D Improve traction
- A In neutral
- B Above posted speed
- C At least 5 mph below the posted curve speed when loaded
- D At posted speed
- A Skip the safety check
- B Allow the receiver to add chemicals
- C Mix freely
- D Verify product compatibility and follow safety procedures
- A Has separate sections for different products
- B Has no baffles
- C Is the same as smooth-bore
- D Has only one section
- A Use only the parking brake
- B Pump rapidly
- C Coast in neutral
- D Use stab braking on non-ABS, full pressure on ABS, and be ready for surge
- A Take a break only
- B Pull over and re-check the load and securement
- C Drive without checking
- D Speed up
- A L restriction
- B H endorsement
- C X endorsement (combination of H and N)
- D P endorsement
- A Back at full speed
- B Use only mirrors
- C GOAL — Get Out And Look — and use a spotter when possible
- D Skip the visual check
- A Permanently mounted to the vehicle
- B A portable tank set on the vehicle
- C All of the above can be a cargo tank
- D A trailer-mounted tank
- A Disregard outage requirements
- B Skip a pre-trip inspection
- C All of the above
- D Drive over the maximum allowable speed for the load
- A Begin unloading immediately
- B Verify the receiver is ready and the receiving tank has capacity
- C Allow the receiver to handle everything
- D Skip the verification
- A All of the above
- B Cause loss of control
- C Cause rollover
- D Push the vehicle through an intersection
- A On curves, ramps, and slick surfaces
- B The tank is partially loaded and surge is highest
- C All of the above
- D Stopping or starting in traffic
- A Open vents while pressure is high
- B Skip the venting
- C Drive while unloading
- D Open vents only after pressure is equalized
- A Improves fuel mileage
- B Operates the brakes
- C Captures vapors during loading and unloading to reduce emissions
- D Reduces engine noise
- A Slow well below posted speed and watch for surge as you change direction
- B Honk and proceed
- C Use the inside lane only
- D Maintain posted speed
- A Is divided into separate compartments
- B Has no internal structure
- C Has internal walls with holes that slow liquid movement
- D Is illegal in the U.S.
- 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
- A Maintain speed
- B Brake earlier and more gently than normal
- C Brake harder to make up for traction loss
- D Use the parking brake
Study tips for the Oklahoma Tank Vehicle exam
The Tank Vehicle portion of the Oklahoma CDL exam is graded out of the bank of questions the Oklahoma 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 Oklahoma 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 Oklahoma 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 Oklahoma 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 Oklahoma 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 Oklahoma 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 Oklahoma Department of Public Safety office.
Already comfortable with this endorsement? Drill another: OK General Knowledge · OK Air Brakes · OK Combination Vehicles · OK Hazardous Materials · OK Passenger · OK School Bus · OK Doubles / Triples
New to the CDL process in Oklahoma? Read How to apply for a CDL in Oklahoma for the document checklist and step-by-step timeline.