North Carolina Tanker CDL Practice Test

This is a free 20-question practice test for the Tanker portion of the North Carolina Commercial Driver's License knowledge exam. Questions are pulled from a pool of 50 drawn from the AAMVA CDL Manual, which is the source document the North Carolina Division of Motor Vehicles uses to write its actual exam.

How it works: Click an answer. The correct choice highlights in green, and you'll see a short explanation. Aim for 85% or better before you sit for the real test in North Carolina.

Question 1 of 20

Tanker pre-trip should specifically check:

Tank shell, intake/discharge/cut-off valves, manhole covers, venting devices, and pressure-relief equipment
Only the tires
Only the engine
Only the placards

Correct. In addition to standard pre-trip, inspect the tank shell, all valves, manhole covers, vents, and pressure-relief devices.

Question 2 of 20

When you drive a tanker on slippery roads, you should:

Drive faster
Reduce speed substantially and increase following distance
Use only the trailer brake
Maintain normal speed

Correct. Reduce speed by at least one-third on wet roads, by half on snow. Liquid loads make recovery from a skid much harder.

Question 3 of 20

When unloading product from a cargo tank, you should:

Verify the receiving container can hold the load, bond and ground, control the flow rate, and remain within 25 feet for flammables
Walk away
Maximize flow rate
Smoke nearby

Correct. Pre-check receiving container, bond and ground, control flow rate to prevent splash and spill, and remain attentive for flammable liquids.

Question 4 of 20

Side-to-side surge is most likely to cause:

Improved fuel economy
Rollover, especially on curves and in evasive maneuvers
No effect
Better braking

Correct. Side-to-side surge can amplify side-loading forces, contributing to rollover on curves and exit ramps.

Question 5 of 20

Front-to-back surge is most likely to cause:

The vehicle to be pushed forward when braking
The vehicle to roll over
Better braking
No effect

Correct. Front-to-back surge pushes the rig forward when you brake — drivers have been pushed through stop lines by an unexpected forward surge.

Question 6 of 20

A tanker with a high center of gravity is most prone to rollover during:

Straight-line driving
Tight curves, evasive maneuvers, and exit ramps
Backing
Stopping

Correct. High center of gravity makes tankers roll on tight curves, sudden lane changes, and exit ramps. Slow well in advance.

Question 7 of 20

When driving a tanker through a sharp bend at the recommended speed for cars:

You are likely to roll over
You are safe
You will accelerate
Brakes engage automatically

Correct. Tanker rollovers regularly happen at posted "car" curve speeds. Slow well below posted speeds in a loaded tanker.

Question 8 of 20

Cargo tanks must be inspected and tested:

Periodically per CFR requirements; intervals depend on tank specification (MC-306, MC-307, MC-312, DOT-406, etc.)
Once a decade
Never
Only when leaks appear

Correct. Cargo tanks have specific inspection and test schedules based on their DOT specification (visual, leakage, internal, pressure, and thickness tests).

Question 9 of 20

Empty tankers handle:

The same as loaded tankers
Differently — lighter axle weight reduces braking traction; tankers are also more affected by crosswinds when empty
Always better
Always worse

Correct. Empty tankers have less brake traction (less weight on tires) and are more affected by crosswinds. Never assume empty equals safer.

Question 10 of 20

Bonding and grounding during product transfer:

Equalizes electrical potential between the tank and receiving container, preventing static-spark ignition
Charges the battery
Cools the load
Speeds delivery

Correct. Static electricity builds up during liquid transfer. Bonding (cable between tank and receiving container) plus grounding equalizes potential to prevent ignition.

Question 11 of 20

You should never load a tank completely full because:

It is illegal in all states
Liquids expand when warmed and need outage; over-filling can rupture the tank
Trucks won't move
It saves no time

Correct. Liquids expand with temperature. Without outage, a warming load can over-pressurize and rupture the tank.

Question 12 of 20

When loading a cargo tank with flammable liquid, the driver must:

Stay alert, within 25 feet, with a clear view of the tank, and ready to handle emergencies
Leave for lunch
Smoke
Run the engine at high RPM

Correct. Federal rule: driver remains within 25 feet, alert, with a clear view, ready to act in case of overflow or emergency.

Question 13 of 20

Pressure relief devices on cargo tanks are designed to:

Open if pressure inside exceeds safe limits, releasing product or vapor before the tank ruptures
Increase pressure
Be tightened down
Stay closed at all times

Correct. Pressure relief valves open at a set pressure to prevent tank rupture. Tampering with them is illegal and dangerous.

Question 14 of 20

When driving with a load that has a low specific gravity (e.g., gasoline) versus high (e.g., asphalt), you should:

Drive the same
Adjust for the differences in surge dynamics, weight distribution, and braking
Skip braking
Run hot

Correct. Different products have different densities, surge characteristics, and weight distributions. Adjust speed and braking for the load.

Question 15 of 20

A "tank vehicle" requiring an N endorsement is generally defined as:

Any commercial vehicle
A vehicle used to transport liquid or gaseous materials in a tank with rated capacity of 1,000 gallons or more, individual tanks of 119+ gallons
Only fuel trucks
Only vehicles over 80,000 lbs

Correct. The N endorsement is required for any commercial vehicle hauling liquid or gas in a permanently mounted tank or portable tank with rated capacity of 1,000+ gallons (and individual tanks of 119+ gallons).

Question 16 of 20

Compartmented tanks have:

Liquid-tight bulkheads dividing the tank into separate sections
No divisions
Smooth interior
Only baffles

Correct. Compartmented tanks have liquid-tight bulkheads. Each compartment is loaded separately, allowing different products in one trailer.

Question 17 of 20

A "bottom-loaded" tank:

Is loaded through bottom valves to reduce vapor and static
Is loaded only at the top
Carries cargo at the bottom only
Has no top vents

Correct. Bottom-loading uses sealed bottom-loading equipment with vapor recovery, reducing static and vapor escape compared to splash-loading from the top.

Question 18 of 20

Tankers should be driven with:

Less following distance
More following distance and gentler control inputs than a dry van
The same as a car
Higher speeds

Correct. Tankers stop slower and roll easier. Increase following distance and use gentler steering and braking inputs.

Question 19 of 20

When emergency-braking a smooth-bore tanker:

Brake hard
Anticipate forward surge that can throw your weight against the wheel and may push the rig past your intended stopping distance
Use only trailer brake
No special concern

Correct. Forward surge can dramatically push a smooth-bore tank rig further than expected. Plan stopping distance with significant additional margin.

Question 20 of 20

A tank with multiple compartments may have:

Different products in each compartment, requiring careful unloading sequence and verification
Only one product
No internal walls
No discharge

Correct. Compartmented tanks (common on fuel-delivery trucks) carry different grades or different products. Verify the destination tank before opening any discharge valve.

About the North Carolina Tanker exam

Most states administer 20 Tanker questions and require 80% to pass. Topics include the unique handling of liquid loads, surge effects, baffles vs. smooth-bore, outage and expansion, inspection of the cargo tank, and emergency procedures.

The North Carolina Division of Motor Vehicles follows the federal CDL standards established by FMCSA. To earn the Tanker credential, you must answer at least 80% of the questions correctly. Many candidates score lower the first time because the test pulls from a large pool — refreshing this page will give you a different mix of questions, drawn from the same authoritative source.

Want more practice? Try the full Tanker question bank or browse all North Carolina CDL practice tests.