Texas Tanker CDL Practice Test

This is a free 20-question practice test for the Tanker portion of the Texas 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 Texas Department of Public Safety Driver License 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 Texas.

Question 1 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 2 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 3 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 4 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 5 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 6 of 20

Tank vehicles should not be driven:

On long downgrades without a lower gear and intermittent firm braking
On any highway
Anywhere
At night

Correct. On long downgrades, select a low gear before starting down and use firm intermittent brake applications to prevent fade.

Question 7 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 8 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 9 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 10 of 20

In the event of a fire on a tanker:

Pull off the road, away from buildings, get out, call 911, and use the ERG to identify the response
Continue to deliver
Pour water on a fuel fire
Drive faster to put out the wind

Correct. Pull to a safe area, away from buildings and people. Get out, call 911, and consult the ERG. Some tank fires (e.g., water on flammable liquid) make matters worse.

Question 11 of 20

Outage refers to:

Empty space left at the top of a tank to allow liquid expansion
The brake-out system
A power failure
A driver shortage

Correct. Outage is the empty space left at the top of a tank to allow liquid to expand as it warms. Different liquids require different outage percentages.

Question 12 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 13 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 14 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 15 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 16 of 20

When carrying water (a non-hazmat liquid) in a tanker, you still need:

The N endorsement, because it is a tank vehicle
No endorsement
Only the H endorsement
Just a Class B

Correct. The N endorsement is based on the vehicle being a tank, not on the cargo. Even non-hazardous water requires the N endorsement if the tank meets size criteria.

Question 17 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 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

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 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 Texas 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 Texas Department of Public Safety Driver License 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 Texas CDL practice tests.