Minnesota Tanker CDL Practice Test

This is a free 20-question practice test for the Tanker portion of the Minnesota 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 Minnesota Driver and Vehicle Services 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 Minnesota.

Question 1 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 2 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 3 of 20

A loaded tanker on a curve is most likely to:

Roll over because surge plus high CG amplifies side forces
Skid in a straight line
Brake faster
Steer easier

Correct. Side surge plus high CG creates a tipping moment well above what a flat-bed of equal weight produces. Speed reduction in advance is the only safe answer.

Question 4 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 5 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 6 of 20

When the surge in a tanker pushes the rig forward at a stop, you may:

Brake harder
Be pushed past the intended stopping point
Skid backward
Have no effect

Correct. Forward surge can push the entire rig forward — past stop lines, into intersections, into the vehicle ahead. Plan your stops with extra distance.

Question 7 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 8 of 20

A double trailer tanker requires:

Both N (Tanker) and T (Doubles/Triples) endorsements, plus possibly H (Hazmat)
Only the N endorsement
No endorsements
Only the H endorsement

Correct. Pulling more than one tank requires Doubles/Triples (T) plus Tanker (N) endorsements. Add Hazmat (H) — together written X — for hazardous liquid loads.

Question 9 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 10 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 11 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 12 of 20

A tanker with an empty compartment between two full compartments may:

Slosh forward and backward, hard to predict
Be smoother
Drive itself
Have no surge

Correct. Mixed full and empty compartments produce complex surge patterns. Plan acceleration and braking conservatively.

Question 13 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 14 of 20

When driving a tanker, you should:

Drive faster on curves
Drive slower than posted curve speeds, especially on exit ramps
Use only the trailer brake
Match car speeds

Correct. Posted advisory speeds assume cars. A loaded tanker may roll over at the posted speed — slow well below posted speeds for ramps and curves.

Question 15 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 16 of 20

Tankers have a high center of gravity because:

The driver sits high
The load is in a tall, narrow tank
The cargo is light
The cab is wide

Correct. A tank carries its load high above the road. The center of gravity is much higher than for a flatbed of the same weight, increasing rollover risk.

Question 17 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 18 of 20

When you discover a leak in a cargo tank carrying flammable liquid:

Continue to the destination
Stop in a safe location, secure the area, contact emergency response and the carrier — never transfer cargo on the road
Try to drive around the leak
Pour water on it

Correct. A leaking flammable cargo tank is a major incident — secure the area, evacuate per the ERG, contact emergency services. Never attempt roadside cargo transfer.

Question 19 of 20

Liquid in a partially filled tank causes:

No special concern
Surge — the load slosh that affects vehicle handling
Better fuel economy
Improved braking

Correct. Surge is the side-to-side or front-to-back movement of liquid in a partially filled tank — it can throw the rig forward, pull it sideways, and significantly affect handling.

Question 20 of 20

A "smooth bore" tank has:

No internal divisions
Internal baffles
Compartments
Reinforcement rings

Correct. A smooth-bore tank has no internal divisions or baffles. Surge is dramatic; brake gently to avoid being pushed forward by the load.

About the Minnesota 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 Minnesota Driver and Vehicle Services 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 Minnesota CDL practice tests.