How many questions are on the Kansas CDL knowledge test?

The Kansas CDL general knowledge test has 50 multiple-choice questions, and you need 80% (40 correct) to pass. The Tanker test is shorter. Most states do not publish its question count, but the 80% pass mark is federal under 49 CFR 383.135 and applies to every CDL knowledge test.

What's the minimum age for a CDL in Kansas?

In Kansas, the minimum age for a CDL is 18 (intrastate); 21 (interstate). Federal law requires drivers to be 21+ to drive a CMV across state lines or to transport hazardous materials, regardless of state minimum age.

Do I need Tanker if the tank is empty?

Usually yes. The endorsement attaches to the vehicle and its bulk capacity rather than to what is in it on the day, so a permanently mounted tank of qualifying size needs the endorsement whether loaded or empty. Riding on an empty tank is also its own hazard, because a partly drained tank surges harder than a full one.

What is the difference between the N endorsement and the X endorsement?

The N endorsement is for tanker vehicles only, meaning liquid or gas cargo in non-hazardous quantities. The X endorsement is a combination of Tanker (N) and HazMat (H), required when you transport hazardous materials in a tank vehicle, such as fuel tankers or chemical tankers. To get an X endorsement, you must pass both the tanker and HazMat knowledge tests.

Why is a partial load more dangerous than a full tank?

A partially filled tank allows liquid to slosh from side to side and front to back, creating liquid surge. This surge can push the vehicle in the direction the liquid moves, making it harder to control during braking, turning, and lane changes. A full tank has minimal surge because there is little room for the liquid to move.

What are baffles in a tank vehicle?

Baffles are internal walls inside a tank that have holes in them to allow liquid to flow through. They reduce the front-to-back surge of liquid, making the vehicle easier to control during braking and acceleration. However, baffles do not prevent side-to-side surge. Smooth-bore (unbaffled) tanks have no internal walls and are used for liquids like milk that must be easily sanitized.

Do I need ELDT for a tanker endorsement?

Yes. Since February 2022, first-time tanker endorsement applicants must complete Entry-Level Driver Training (ELDT) through an FMCSA-registered training provider. This applies to anyone adding the N endorsement for the first time. It does not apply if you are renewing or transferring an existing tanker endorsement.

What vehicles require a tanker endorsement?

Any commercial vehicle designed to transport any liquid or gaseous material in a tank or tanks with an individual rated capacity of 119 gallons or more, or a combined rated capacity of 1,000 gallons or more, requires a tanker endorsement. This includes fuel tankers, water trucks, milk tankers, and portable tank containers.

Kansas CDL tanker practice test

Updated for 2026 · 39 tanker questions of 473 across the full KS CDL path · Aligned to the commercial driver manual · Part of the KS CDL path

Start with general knowledge first. We recommend completing it before drilling tanker questions.

Combine Tanker with HazMat (the X endorsement) if you plan to haul fuel or chemical tankers — that's the highest-paying tanker work.

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Required to haul liquids or gases in bulk. The core skill is surge: liquid moving inside the tank changes your braking, your stability and how you take a curve.

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About the Kansas Tanker test

A separate written exam at the federal 80% pass mark. States rarely publish a question count for it, so plan on knowing the whole section rather than a fixed number of items. Questions focus on liquid surge and its effect on vehicle handling, the dangers of partial loads vs. full loads, proper braking and cornering techniques for tank vehicles, baffled vs. unbaffled tanks, outage requirements (why tanks are never filled completely), and emergency procedures. If you are combining the tanker endorsement with HazMat (X endorsement), expect additional questions on hazardous liquid transport. This is a separate knowledge test from General Knowledge, required in every state under 49 CFR 383.71, and the DOR publishes the Kansas Commercial Driver's License Manual as the study source for it.