Official exam: CDL General Knowledge (South Carolina)
Take a free South Carolina CDL practice test online: a full 50-question paper with every answer explained, no sign-up, scored by topic. The full 124-question bank and the timed simulator are $14.99 for 30 days.
CDL General Knowledge (South Carolina): a 124-question practice bank for the real CDL Permit & Endorsement Exams standard, 2 full papers of 50 questions each with no repeats, every question written to the regulation it comes from.
Where these questions come from
Every question in this bank cites a source -- primarily FMCSA CDL Manual (77%) and 49 CFR (23%) of this exam's citations.
Take a full practice test free. 50 real questions built to the exam's domain weights, every answer explained, no sign-up required, with a domain-by-domain score at the end.
Want the whole bank for CDL General Knowledge (South Carolina)? One payment of $14.99 gives you 30 days of full access to this exam. It does not renew. No account needed to buy, and there is a 7-day money-back guarantee.
The knowledge tested here is federal (FMCSA) and identical nationwide -- what varies by state is who administers it and under what terms. Researched directly from South Carolina Department of Motor Vehicles (SCDMV)'s own site, verified 2026-09-03.
$15 application fee + $2 per knowledge test + $2.50 CLP card fee (per dmv.sc.gov/Driver-Services/Commercial-Licenses/Getting-Your-First-CDL)
Road/skills test fee
$25 fee to retake the skills test after a failure; original skills test fee not separately itemized on the pages checked
Minimum CLP hold before road test
14 calendar days (state page states: "You must wait 14 days from the date your original commercial learner's permit (CLP) was issued before you are eligible to take the skills test") -- matches federal 14-day floor
CLP validity
1 year (one-year expiration date)
Retake wait after a failed knowledge test
Skills test: 2 business days after 1st failure; 7 calendar days after 2nd failure; 30 calendar days after 3rd or subsequent failure (dmv.sc.gov CDL Testing page)
Spanish-language knowledge test
Unconfirmed
Could not confirm from an SCDMV primary source whether the CDL knowledge test itself is offered in Spanish. SCDMV pages confirm a free ASL (American Sign Language) translator is furnished for hearing-impaired CDL knowledge test takers, but no SCDMV page found in this research explicitly lists Spanish (or other spoken-language) availability for the CDL knowledge test specifically, and third-party aggregator claims about Spanish availability could not be verified against dmv.sc.gov. No SCDMV notice of a 2025/2026 policy change was found. Recommend calling SCDMV CDL Help Desk (803-896-2673) to confirm before publishing.
SC requires FMCSA-approved ELDT (Entry-Level Driver Training) completion for any CLP issued after February 7, 2022, before the CDL skills test can be taken.
SCDMV furnishes and pays for a certified ASL translator for hearing-impaired applicants taking the CDL knowledge test.
5 real sample questions
What is the most important reason for performing a pre-trip inspection before every trip?
A. To satisfy your dispatcher that the truck left on time
B. To find problems that could cause a crash or breakdown before they happen on the road
C. To reduce the number of miles logged for the day
D. To avoid having to fill out any paperwork later
Show answer and reasoning
Correct answer: B. To find problems that could cause a crash or breakdown before they happen on the road
A: A pre-trip inspection has nothing to do with dispatch timing.
C: Inspection findings do not change logged mileage.
D: A pre-trip inspection actually creates required paperwork (the inspection report), not less of it.
Source: FMCSA CDL Manual §2.1.1
A roadside inspector determines that a commercial motor vehicle has a safety defect serious enough to be an immediate hazard. What is the inspector authorized to do under 49 CFR 396.9?
A. Issue a warning only, since only the motor carrier can pull a vehicle from service
B. Declare the vehicle "out of service" until the defect is corrected
C. Impound the vehicle permanently
D. Fine the driver but allow the vehicle to continue to the next scheduled stop
Show answer and reasoning
Correct answer: B. Declare the vehicle "out of service" until the defect is corrected
A: 396.9 gives the inspector authority to declare the vehicle out of service, not merely to warn.
C: Out-of-service means repaired and released, not permanent impoundment.
D: An out-of-service order prohibits further operation until the defect is fixed, not a fine-and-continue arrangement.
Source: 49 CFR 396.9
Under the federal tire tread depth standard, what is the minimum tread depth allowed in any major tread groove on a steering axle tire?
A. 1/32 inch
B. 2/32 inch
C. 4/32 inch
D. 6/32 inch
Show answer and reasoning
Correct answer: C. 4/32 inch
A: 1/32 inch is below the federal minimum for any position.
B: 2/32 inch is the minimum for tires on axles other than the steering axle.
D: 6/32 inch is deeper than the regulation requires, though additional depth is never unsafe.
Source: 49 CFR 393.75
What is the minimum tread depth required on non-steering axle tires of a commercial motor vehicle?
A. 1/32 inch
B. 2/32 inch
C. 3/32 inch
D. 4/32 inch
Show answer and reasoning
Correct answer: B. 2/32 inch
A: 1/32 inch is too shallow to meet the federal standard for any tire position.
C: 3/32 inch is not the regulatory threshold; the rule specifies 2/32 inch for non-steering tires.
D: 4/32 inch is the steering-axle minimum, not the standard for other axle positions.
Source: 49 CFR 393.75
Under 49 CFR 392.7, a driver may not operate a commercial motor vehicle unless satisfied that certain systems are in good working order. Which of the following is included in that pre-trip requirement?
A. The radio and cab air-conditioning system
B. Service brakes, trailer brake connections, parking brake, tires, lights, and mirrors
C. The cruise control set speed
D. The fuel economy displayed on the dashboard computer
Show answer and reasoning
Correct answer: B. Service brakes, trailer brake connections, parking brake, tires, lights, and mirrors
A: Comfort features like radio and A/C are not part of the 392.7 safety-systems check.
C: Cruise control settings are a convenience feature, not a listed safety system.
D: Fuel economy readouts are informational only, not a safety-critical system under 392.7.
Where can I take a free South Carolina CDL practice test online?
Right here. CertQuestUSA's free South Carolina CDL practice test online is a full 50-question practice paper built to the real exam's domain weights, with every answer explained, with no sign-up and no credit card, and shows your score by topic at the end. The full 124-question bank, with every answer explained and cited to the regulation it comes from, is $14.99 for a 30-day pass that never renews.
How many questions are on the CertQuestUSA CDL General Knowledge (South Carolina) practice test?
124 questions total, split into 2 full papers of 50 each with no repeats across papers.
What topics does the CDL General Knowledge (South Carolina) test cover?
13 domains, with the heaviest weight on Vehicle Inspection (14%), Basic Control & Shifting (10%), and Emergency Maneuvers & Skid Control (10%).
Where do CertQuestUSA's CDL General Knowledge (South Carolina) questions come from?
Primarily FMCSA CDL Manual (77%) and 49 CFR (23%) of this bank's citations -- computed directly from this exam's own question sources, not a generic description.
Is there a free CDL General Knowledge (South Carolina) practice test?
Yes -- one full 50-question practice paper built to the exam's domain weights, free with no sign-up, with every answer explained and a domain-by-domain score at the end.
Still need a CDL school, a DOT physical, or tuition help?
CDL Schools USA, our sister site, lists FMCSA-registered schools by state, paid training programs, DOT physical clinics, and WIOA and GI Bill funding.
