About the Tanker (N) Test
The Tanker endorsement is required to drive a vehicle hauling liquids or gases in bulk. Tankers carry a high center of gravity and a load that moves, which makes them some of the trickiest rigs to control. The test focuses on the physics of that moving load and how to drive around it safely.
You'll see questions on liquid surge, outage (the room you must leave for a liquid to expand), baffled versus unbaffled and smooth-bore tanks, why you brake and corner gently, and inspection of the tank and its valves. It's commonly 20 to 25 questions with an 80% pass mark, and most states require no separate skills test for it.
What Test-Takers Miss Most
- 1Liquid surge and smooth braking — Why surge pushes the truck forward at stops, and why gentle, early braking and extra following distance are the answer.
- 2Outage and density — Why you can't fill a tank completely, and how the liquid's density changes how much you can legally carry.
- 3Baffled vs. unbaffled tanks — How baffles reduce front-to-back surge but not side-to-side, and why smooth-bore tanks are the most demanding to drive.
Choose Your State
Each state's test reflects its own CDL handbook, question count, and passing score. Pick yours to start a free Tanker (N) practice test built for 2026.