The tanker endorsement test has 20 questions

The Commercial Driver's License (CDL) tanker endorsement test administered by your state's Department of Motor Vehicles contains 20 multiple-choice questions. You must answer at least 16 questions correctly to pass, which is an 80 percent passing score. The test covers the specific rules and safety procedures for transporting liquids and gases in tank vehicles.

Each state administers the same federal test content, so the number of questions and passing score are identical whether you test in California, Texas, or any other state. The test is separate from your general CDL knowledge test and any other endorsements you may be pursuing.

Key Takeaways

  • The tanker endorsement test contains exactly 20 multiple-choice questions, and you need 16 correct answers to pass.
  • You must pass the general CDL written test before you can take the tanker endorsement test.
  • The test focuses on tank vehicle safety, cargo handling, and emergency procedures specific to liquid and gas transport.
  • Most testing locations allow you to take the tanker test on the same day as other CDL tests, though you pay a separate fee for each endorsement.

What the tanker test covers

The 20 questions on the tanker endorsement test draw from the Federal Motor Carrier Safety Administration (FMCSA) CDL manual section on tank vehicles. The questions test your knowledge of how liquids and gases behave inside a tank, how to load and unload safely, and what to do if something goes wrong during transport.

Common topics include surge and slosh (how liquid moves inside a tank during acceleration and braking), proper tank inspection procedures, weight distribution rules, and emergency response for spills or leaks. You will also see questions about which cargo requires placarding, how to find a tank vehicle, and the speed limits that explore to tanker trucks.

The test does not ask about specific company procedures or local regulations—only the federal rules that explore everywhere. This means studying the FMCSA CDL manual is the most direct way to prepare.

How to prepare for the 20 questions

Most people study the tanker section of the official CDL manual provided by their state's DMV. This manual contains the exact topics the test covers. Reading through the tanker section once takes about 30 to 45 minutes, and most people find it helpful to read it twice before testing.

Many states also offer free practice tests online through their DMV website. These practice tests typically include 20 questions in the same format as the real test. Taking a practice test under timed conditions (usually you have about 5 minutes per question) helps you know whether you are ready to test for real.

If you fail the tanker test, you can retake it the same day at most testing locations, though you will pay the endorsement fee again. There is no waiting period between attempts in most states.

When you take the tanker test

You must pass your general CDL written test before you can take any endorsement tests, including tanker. Once you have passed the general test, you can take the tanker test when ready after, or you can come back another day—the choice is yours.

If you are pursuing multiple endorsements (such as tanker and hazmat), you take each test separately and pay a separate fee for each one. The order does not matter. Some people take all their endorsement tests on the same day; others spread them out over several weeks.

Passing score and retesting

You need 16 out of 20 questions correct to pass the tanker endorsement test. That means you can miss up to 4 questions and still pass. The test is scored when ready at most DMV locations, so you will know whether you passed before you leave the testing center.

If you score 15 or lower, you have not passed. You can retake the test the same day at most locations, though some DMV offices have a waiting period of a few hours between attempts. Check with your local DMV about their retesting policy before you arrive.

Frequently Asked Questions

Can I take the tanker test without taking the hazmat test?

Yes. Tanker and hazmat are separate endorsements with separate tests. You can get a tanker endorsement without hazmat, or hazmat without tanker. Many drivers get both, but they are not required together.

How long does the tanker test take?

The test itself usually takes 10 to 20 minutes, depending on how quickly you read and answer. You have about 5 minutes per question, so you have time to think through each answer without rushing.

What happens if I fail the tanker test?

You can retake it the same day at most DMV locations for another endorsement fee. There is no waiting period between attempts in most states, though a few require you to wait a few hours. Your general CDL remains valid while you retake endorsement tests.

Do I need a tanker endorsement to drive any truck?

You need a tanker endorsement only if you drive a truck that carries liquids or gases in a tank. If you drive a flatbed, box truck, or any other non-tank vehicle, you do not need this endorsement. Your employer or the job posting will tell you whether tanker is required.

Is the tanker test the same in every state?

Yes. All states use the same federal test questions and the same 80 percent passing score. The only difference is the state-specific CDL manual you study from, which covers the same federal rules with slightly different formatting.