Hawaii Tanker CDL Practice Test

This is a free 20-question practice test for the Tanker portion of the Hawaii 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 Hawaii Driver License Office 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 Hawaii.

Question 1 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.

Question 2 of 20

A "baffled" tank has:

Walls with holes that slow surge but allow flow
No walls
Only one compartment
Outside reinforcement

Correct. Baffled tanks have internal bulkheads with holes — they slow surge but still allow product to flow through during loading and unloading.

Question 3 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 4 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 5 of 20

A loaded tanker traveling 10 mph above the safe curve speed has a:

Lower rollover risk
Significantly higher rollover risk because rollover threshold scales with speed squared
Same risk
Better handling

Correct. Centripetal force scales with speed squared. Just 10 mph over safe speed can take you past the rollover threshold of a loaded tanker.

Question 6 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 7 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 8 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 9 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 10 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 11 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 12 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 13 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 14 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 15 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 16 of 20

Tank specification "MC-306" or "DOT-406" generally refers to:

Cargo tanks designed for non-pressure flammable and combustible liquids (e.g., gasoline, diesel)
High-pressure gases
Cryogenic liquids
Hazardous solids

Correct. MC-306 (older) and DOT-406 (current) are non-pressure cargo tanks for flammable and combustible liquids — typical fuel tankers.

Question 17 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 18 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 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

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.

About the Hawaii 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 Hawaii Driver License Office 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 Hawaii CDL practice tests.