Arizona Tanker CDL Practice Test

This is a free 20-question practice test for the Tanker portion of the Arizona 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 Arizona Motor Vehicle Division 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 Arizona.

Question 1 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 2 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 3 of 20

Vapor recovery during loading:

Is used at terminals to capture flammable vapors
Replaces the cargo
Is forbidden
Is used only at night

Correct. Vapor recovery captures flammable vapors displaced as product is loaded, returning them to storage. Required at most modern fuel terminals.

Question 4 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 5 of 20

Outage requirements:

Vary by liquid because of differing thermal expansion rates
Are always 1 percent
Do not exist
Are only for water

Correct. Outage requirements differ by product. Gasoline expands more than diesel, ethanol expands differently, etc. Check the shipping paper or product specifications.

Question 6 of 20

A tanker hauling food-grade product (e.g., milk):

Often uses a smooth-bore tank for cleaning
Uses a baffled tank
Uses a compartmented tank only
Uses no tank

Correct. Smooth-bore tanks (no internal baffles) are easier to clean for food-grade products. The trade-off is severe surge — drive slower and brake earlier.

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 pressure-relief device that vents during transit:

Is a normal occurrence
Is a serious malfunction or over-fill — stop and investigate
Means the tank is empty
Means the load is cold

Correct. Continuous venting indicates over-pressure (often from over-fill or sun heating an over-filled tank). Stop and investigate; do not continue with a venting tank.

Question 9 of 20

Carrying a smooth-bore tank up a ramp or off a curb:

Causes minimal surge
Can produce strong front-to-back surge that affects throttle and traction
Has no effect
Improves traction

Correct. Climbing causes the load to surge backward and then forward as you level off — affecting throttle response, traction, and braking.

Question 10 of 20

On a wet road, a tanker should:

Maintain normal speed
Reduce speed by about one-third
Drive faster
Use only the trailer brake

Correct. On wet pavement, reduce speed by about one-third. On snow, by about one-half. Tankers are less forgiving than dry vans on slippery roads.

Question 11 of 20

When braking a partially filled smooth-bore tank, you should:

Brake hard at the last minute
Brake gently and start braking earlier than usual to compensate for surge
Use only the trailer hand valve
Pump the brakes

Correct. In smooth-bore tanks, surge is severe. Brake gently and earlier than you would in a dry-van trailer to avoid being pushed forward.

Question 12 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 13 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.

Question 14 of 20

The driver should plan extra time for:

Acceleration, braking, and turning a fully loaded tanker
Lunch
Sleep only
Refueling only

Correct. A loaded tanker accelerates slower, brakes longer, and turns wider. Plan your trip and reactions accordingly.

Question 15 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 16 of 20

A heavy liquid load with a baffled tank may still surge:

Front-to-back, despite the baffles
Not at all
Less than smooth-bore but baffles do not stop side-to-side surge
None of the above

Correct. Baffles reduce front-to-back surge but do not affect side-to-side surge — bulkheads are typically transverse, not longitudinal.

Question 17 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 18 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 19 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 20 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).

About the Arizona 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 Arizona Motor Vehicle Division 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 Arizona CDL practice tests.