CDL Tank Vehicles Practice Test 2026
Free CDL Tank Vehicles (Tanker / N endorsement) practice β required to haul liquids or gases in bulk tanks. Real test is in English; native-language explanations + English-term glossary. ~20 questions on the real test, 80% to pass. Practice every question free, then sit a 20-question mock scored to the real 80% pass line.
π CDL pre-trip inspection β step by step
A step-by-step pre-trip checklist β the 7-step method, engine, walkaround and the in-cab air brake check, with the auto-fail points β
π― Practice by Topic
Inspecting Tank Vehicles
Inspecting a tank vehicle: checking for leaks (you cannot drive a leaking tank), and checking the special-purpose and emergency equipment tank vehicles carry (vapor-recovery, special cut-off systems, etc.).
Driving Tank Vehicles
Why tank vehicles are harder to drive: the high center of gravity (rollover risk), the danger of liquid surge in a partially filled tank, bulkheads vs baffled vs smooth-bore (un-baffled) tanks, outage (room for the liquid to expand), and how much you can load.
Safe Driving Rules
Driving a tank vehicle safely: drive smoothly, control surge when braking (brake early, keep extra following distance), slow down for curves below the posted speed, allow for a longer stopping distance, and recover from skids.
π Study guides for this exam
π§° Jobs this credential opens
See jobs βπ§ Where this leads β the new immigrant career path
See how this exam fits a step-by-step ladder of U.S. licenses and certs β with median pay and the languages each real exam is offered in β
π What to Bring
- β
Existing CDL or Commercial Learner's Permit
The N endorsement is added on top of a CDL.
- β
Proof of identity & required documents
Bring the documents your state DMV lists for adding an endorsement.
π How to Schedule
- 1
Study Section 8 (Tank Vehicles)
Cover inspecting tank vehicles (leaks, special equipment, vapor/pressure), driving safely with a high center of gravity and liquid surge (baffled vs. smooth-bore/unbaffled tanks, outage, density), and emergency handling. Bulkheaded tanks and partial loads (front-to-back vs. side-to-side surge) are heavily tested.
- 2
Pass the Tank Vehicles knowledge test (in English) at your DMV
About 20 questions, 80% to pass. This endorsement is knowledge-test only. Fees and scheduling vary by state.
π‘ Test Day Tips
- β’Learn the key English terms even if you study in Chinese/Spanish: liquid surge, baffle, smooth-bore (unbaffled) tank, bulkhead, outage, center of gravity, gallons.
- β’Master the high-stakes safety facts: tankers have a high center of gravity and liquid surge, so slow down well below posted curve speeds and brake early; smooth-bore (unbaffled) tanks have the worst forward-and-back surge β wait for the surge to settle before easing off the brake; and never over-fill β you must leave outage for the liquid to expand.
- β’Know why you can't always fill a tank: liquids expand as they warm (you must leave outage), and the legal weight depends on the liquid's density β a tank that fills to legal weight with one product would be overweight with a denser one.
π Study Handbook
All practice questions are based on the sections below. Click any to read the official source.
π Official Resources
β Frequently asked questions
How many questions are on the CDL Tank Vehicles test, and how many do I need to pass?
The CDL Tank Vehicles knowledge test has 20 questions. You must answer 16 correctly (80%) to pass.
How many questions can you miss on the CDL Tank Vehicles test?
You can miss up to 4 of the 20 questions and still pass.
What should I bring to the CDL Tank Vehicles test?
Existing CDL or Commercial Learner's Permit β The N endorsement is added on top of a CDL. Proof of identity & required documents β Bring the documents your state DMV lists for adding an endorsement.
How do I schedule and take the CDL Tank Vehicles test?
1. Study Section 8 (Tank Vehicles): Cover inspecting tank vehicles (leaks, special equipment, vapor/pressure), driving safely with a high center of gravity and liquid surge (baffled vs. smooth-bore/unbaffled tanks, outage, density), and emergency handling. Bulkheaded tanks and partial loads (front-to-back vs. side-to-side surge) are heavily tested. 2. Pass the Tank Vehicles knowledge test (in English) at your DMV: About 20 questions, 80% to pass. This endorsement is knowledge-test only. Fees and scheduling vary by state.