CDL Tanker Endorsement Practice Test
The Tanker endorsement (N) is required whenever you're hauling a liquid or gas in a permanent tank or a portable tank with a capacity of 1,000 gallons or more. It changes the way the truck handles — liquid surge shifts weight forward under braking and side to side in curves, and a high center of gravity makes rollovers more likely.
This free CDL Tanker practice test covers the physics you'll be tested on: liquid surge, baffled vs. unbaffled vs. smooth-bore tanks, outage requirements for different liquids, and the special driving techniques you use behind the wheel of a full tanker.
What this test covers
- Liquid surge and how it affects braking, acceleration, and steering
- Baffled, unbaffled (smooth-bore), and compartmented tanks
- Outage: why liquids need room to expand and how much to leave
- High center of gravity and rollover risk
- Front-to-back and side-to-side surge
- Inspecting a tank vehicle
- Emergency systems: shut-off valves, vents, and manholes
How to study
- Understand the difference between baffled and smooth-bore tanks — smooth-bore is common for food-grade tankers and requires slower, smoother driving.
- Learn typical outage rules: about 2% for most liquids, more for those that expand a lot with heat.
- If you also need HazMat, most drivers combine Tanker and HazMat (X endorsement) — study both together.
Frequently asked questions
- When do I need the Tanker endorsement?
- Anytime you're hauling a liquid or gas in a tank with an individual capacity of 119 gallons or more AND an aggregate capacity of 1,000 gallons or more, permanently or temporarily mounted on the vehicle.
- How many questions are on the Tanker endorsement test?
- Most states give a 20-question Tanker knowledge test that requires 80% (16 out of 20) to pass. Check your state DMV for the exact count.
- What's the difference between Tanker (N) and HazMat (H)?
- Tanker covers the physics of hauling liquids and gases (surge, outage, rollover). HazMat covers placarding, shipping papers, and safe transport of regulated materials. Drivers hauling hazardous liquids in bulk typically need both — combined as the X endorsement.
Ready to start?
Practice this CDL topic free — no account needed for your first session. Unlock the full course when you're ready.