What the Minnesota Tanker Endorsement Covers

The Minnesota tanker endorsement (also called the T endorsement) is required to operate any commercial vehicle designed to carry liquid cargo in bulk — including gasoline, diesel, milk, water, or hazardous materials. You cannot legally haul liquids in a tank vehicle without this endorsement on your CDL, even if you hold a Class A or Class B license.

The endorsement itself does not require you to carry hazardous materials. A tanker endorsement and a hazmat endorsement are separate. You can hold a tanker endorsement and haul non-hazardous liquids (milk, water, food-grade oils) without the hazmat endorsement. However, if you want to haul hazardous liquids like gasoline or propane, you must hold both endorsements plus pass the hazmat background check.

Minnesota's tanker test focuses on the physics and handling of liquid cargo, the rules for different tank types, and the specific safety procedures required by state and federal law. The test is written only — there is no separate skills test for the tanker endorsement.

Key Takeaways

  • The tanker endorsement test in Minnesota covers liquid surge, baffles, compartments, safe braking with liquid loads, and federal tank specifications.
  • You must pass a 20-question multiple-choice test with a score of at least 80 percent (16 correct answers) to earn the endorsement.
  • Study materials are available free from the Minnesota Department of Public Safety website, including the official CDL manual and tanker-specific sections.
  • You take the test at any Minnesota Driver and Vehicle Services (DVS) exam station; no appointment is required for the written test, though wait times vary by location.
  • The tanker endorsement costs $20 and is valid for eight years, the same term as your CDL.

What Topics Appear on the Minnesota Tanker Test

The Minnesota tanker endorsement test draws from the Federal Motor Carrier Safety Administration (FMCSA) CDL manual, with questions specific to tank vehicle operation. The test covers five main areas: tank construction and types, liquid surge and slosh, safe handling and braking, loading and unloading procedures, and emergency response.

Tank construction includes questions about baffles (internal dividers that slow liquid movement), compartments (separate sections within one tank), and the difference between smooth-bore and baffled tanks. You will see questions about why certain tank types are required for certain liquids and what happens when a tank lacks proper baffles.

Liquid surge and slosh is the physics section. Liquid inside a tank does not move with the vehicle the way solid cargo does — it sloshes forward during braking and backward during acceleration. The test asks you to explain how surge affects braking distance, why you must brake differently with a full tank versus a partially full tank, and how to prevent rollover when turning. This is the section where most drivers struggle, because the answers are not intuitive.

Safe handling and braking covers the practical rules: you must brake smoothly and gradually, avoid sudden steering movements, never use the engine brake (Jake brake) on slippery surfaces with a tanker load, and maintain extra following distance. Questions ask what to do if you feel the tank shifting during a turn, or how to recover if the rear wheels start to slide.

Loading and unloading includes rules about weight distribution, placarding requirements, and the paperwork you must carry. You will see questions about how to position the vehicle during loading, whether you can leave the vehicle unattended during transfer, and what documents the shipper must provide.

Emergency response covers what to do if the tank ruptures, leaks, or overturns. Questions ask about evacuation procedures, when to call hazmat teams, and your responsibility to warn other drivers and protect the scene.

How to Study for the Tanker Endorsement Test

The official study material is the Minnesota CDL Manual, published by the Department of Public Safety. The tanker section is typically 8 to 12 pages and covers all topics that appear on the test. You can read the manual free from the Minnesota DVS website or request a printed copy at any DVS office.

Read the tanker section at least twice. On the first pass, read straight through to understand the concepts. On the second pass, take notes on the key differences between tank types, the rules for braking with liquid loads, and the emergency procedures. Write down any terms you do not recognize — surge, slosh, baffles, compartments, smooth-bore — and make sure you can explain each one in your own words.

Practice tests are available through several sources. The Minnesota DVS website does not publish official practice questions, but the FMCSA manual includes sample questions at the end of each section. Third-party CDL study sites (such as those run by truck driving schools) often include tanker practice tests; these are not official but follow the same format and topic areas as the real test. Take at least two full-length practice tests before your exam date. If you score below 80 percent on a practice test, review the section where you missed questions and take another practice test on that topic only.

If you are studying on your own, set aside 4 to 6 hours over one to two weeks. If you are enrolled in a truck driving school, the school will provide tanker instruction as part of the CDL curriculum, usually 2 to 4 classroom hours plus practice tests. Do not skip this instruction even if you think you already know how to drive a tanker — the test focuses on specific federal rules and physics concepts that differ from on-the-job experience.

Test Format and Passing Score

The Minnesota tanker endorsement test is a written exam with 20 multiple-choice questions. Each question has four answer choices. You must answer at least 16 questions correctly (80 percent) to pass. You have one hour to complete the test, though most drivers finish in 15 to 20 minutes.

The test is administered on a computer at any Minnesota DVS exam station. You will sit at a private testing terminal, and your answers are scored when ready after you submit. If you pass, you will receive a receipt showing your score and the date your endorsement becomes valid. If you fail, you can retake the test the same day or return another day — there is no waiting period between attempts in Minnesota, though you must pay the $20 fee each time you test.

The test is offered in English only. If you need language information, contact your local DVS office before your test date to arrange an interpreter or translated materials; this must be requested in advance and is not available at all locations.

Documents and Fees You Will Need

Bring your current CDL or learner's permit and a valid form of identification (passport, state ID, or military ID). You do not need to bring study materials or notes — they are not allowed in the testing area.

The tanker endorsement costs $20 in Minnesota. This fee is separate from any CDL renewal or upgrade fees. Payment is made at the DVS office when you register for the test. If you fail and retake the test, you pay the $20 fee again for each attempt.

Once you pass, the endorsement is added to your CDL at no additional cost. The endorsement is valid for eight years, matching the validity period of your CDL. When you renew your CDL, you can renew the tanker endorsement at the same time for the standard renewal fee.

Where to Take the Test in Minnesota

The tanker endorsement test is offered at all Minnesota Driver and Vehicle Services exam stations. There are 23 DVS stations across the state, located in the Twin Cities, Rochester, Duluth, St. Cloud, Mankato, and other major cities. You do not need an appointment for the written test — you can walk in during business hours and register on the spot, though wait times vary. During peak hours (mid-morning and early afternoon on weekdays), you may wait 30 minutes to an hour. Early morning or late afternoon visits typically have shorter waits.

You can find the address, phone number, and hours of your nearest DVS station on the Minnesota Department of Public Safety website. Some stations close for lunch or have limited hours on certain days, so check before you go. If you live in a rural area far from a DVS station, you may be able to test at a satellite location or request a mobile testing unit, though availability is limited — call ahead to confirm.

Common Mistakes on the Tanker Test

The most common mistake is misunderstanding how liquid surge affects braking. Many drivers assume that a full tank is safer because there is more weight, but the test asks the opposite: a full tank actually increases braking distance because the liquid has more mass to move. A partially full tank is more dangerous because the liquid can slosh more freely, creating unpredictable weight shifts. If you miss questions about braking or rollover, reread the surge and slosh section of the manual and focus on the physics, not just the rules.

The second common mistake is confusing tank types. The test asks about smooth-bore tanks (no internal dividers), baffled tanks (with dividers), and compartmented tanks (separate sealed sections). Each type is used for different liquids and has different handling characteristics. Make a chart showing which tank type is used for which cargo and why — this visual aid helps many drivers remember the distinctions.

The third mistake is not reading the answer choices carefully. Tanker questions often have two answers that sound similar, with one being slightly more correct or more specific. Read all four choices before selecting, and if two seem right, pick the one that is most specific or most directly answers the question asked.

Frequently Asked Questions

Do I need a tanker endorsement if I only haul non-hazardous liquids like milk or water?

Yes. The tanker endorsement is required for any bulk liquid cargo, whether hazardous or not. The endorsement certifies that you understand liquid surge, tank safety, and proper handling procedures. A hazmat endorsement is separate and only required if you haul hazardous liquids like gasoline or propane.

Can I take the tanker test without a CDL yet, or do I need to have my CDL first?

You must have a valid CDL or a CDL learner's permit before you can test for the tanker endorsement. If you do not yet have your CDL, you must pass the general CDL written test and skills test first, then add the tanker endorsement afterward.

What happens if I fail the tanker test?

You can retake the test when ready or on another day — there is no waiting period in Minnesota. You pay the $20 fee each time you test. Most drivers who fail pass on the second attempt after reviewing the sections where they missed questions.

How long is the tanker endorsement valid?

The tanker endorsement is valid for eight years, the same as your CDL. When your CDL expires, you can renew the tanker endorsement at the same time during your CDL renewal.

Is the tanker test harder than the general CDL test?

The tanker test is shorter (20 questions versus 50 for the general CDL test) but covers more specialized material. Many drivers find the physics of liquid surge more difficult than general driving rules, so it requires focused study. The passing score is the same: 80 percent.