Iowa Tanker Test — Quick Facts
FormatWritten knowledge test
Questions20 questions
Passing score80% (16/20)
Min. age (intrastate / interstate)18 / 21
CLP hold before skills test14 days min
Government feeSee Iowa DMV →
Start the Free Iowa Tanker Test →
20 questions · one per page · your progress saves automatically
Iowa Tanker Practice Tests
3 full practice tests, each with 20 questions drawn from the Iowa CDL question bank. Your score and progress save as you go.
About the Iowa Tanker Test
The Tanker (N) endorsement covers liquid and gas bulk loads in Iowa. A partially full tank handles like nothing else on the road, so the test focuses on liquid surge, a high center of gravity, outage, baffles, and smooth braking.
PM
From Pedro, behind the wheelI run tankers, and liquid surge is no joke — a half-empty smooth-bore tank will push you through an intersection after you've stopped. Take the outage and baffle questions slow.
What Test-Takers Miss Most
- 1Liquid surge and smooth, early braking
- 2Outage and how density limits your load
- 3Baffled vs. unbaffled and smooth-bore tanks
Iowa CDL Requirements & Fees
Iowa follows the federal CDL framework: a minimum age of 18 for intrastate driving and 21 for interstate, a commercial learner's permit you must hold at least 14 days before the skills test, and the 80% passing standard. License fees and retake rules are set by Iowa and change from time to time, so check the official source below for current amounts before you go in.
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Official Iowa CDL Handbook & FeesCurrent requirements, fees, and the manual this test is based on
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Frequently Asked Questions
How many questions are on the Iowa CDL Tanker test?
The Tanker test has 20 questions, and you need 16 correct to pass at the 80% threshold used across the U.S. under FMCSA standards. Exact counts can vary slightly by state, so confirm with the Iowa CDL handbook.
What score do I need to pass in Iowa?
You need 80% — that's 16 of 20 questions correct on the Tanker test.
How much does a Iowa CDL cost?
CDL fees are set by Iowa's licensing agency and change periodically, so we don't quote a figure that could go stale. Check current amounts on the official Iowa CDL page.
Is this Iowa practice test free and accurate?
Yes — it's completely free, based on the Iowa CDL handbook, and written and verified by Pedro Marin, an active CDL holder. No registration required.
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