Commercial DrivingFederal certification87 free questions
CDL: Tanker (N)
N endorsement: liquid surge, baffles vs smoothbore, outage and high center of gravity.
10
practice questions
9
free questions
8%
of the real exam
What this section covers
The N (tank vehicle) endorsement is typically 20 questions, 80%. You need it for tanks that carry liquid or gas in bulk — not every tank-shaped body, but the ones the state lists as tank vehicles.
The test is about how liquid moves:
- Forward / back / side surge
- Baffles cut front-to-back surge; they do little for side-to-side
- Smoothbore (unbaffled) tanks are the worst for surge
- Outage (expansion space) and a high center of gravity
- Smooth steering, early braking, no sudden lane changes
Hauling placarded product in a tank usually needs H and N (often X). Practice: Tanker.