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Exam Review

Key Facts: Oklahoma CDL General Knowledge Exam

80%

Minimum passing score for CDL knowledge tests

FMCSA / 49 CFR 383.135

At least 30

Minimum basic knowledge-test items

FMCSA States CDL Knowledge & Skills Test

20

General knowledge areas for CMV operators

49 CFR 383.111(a)

$25

CareerTech ServiceOK fee for one CDL exam in a test session

Oklahoma CareerTech ServiceOK Licenses

Oklahoma CDL applicants should study the Service Oklahoma CDL Driver Manual before taking the General Knowledge written test. Under FMCSA standards, the basic CDL knowledge test covers the 20 general areas in 49 CFR 383.111(a), has at least 30 multiple-choice items, and requires at least 80% correct to pass. CareerTech ServiceOK CDL written testing fees are published as $25 for one exam in a session, with tiered pricing up to $40 for four exams. Separate air-brake, combination-vehicle, and endorsement tests may be required depending on the vehicle and CDL class sought.

Sample Oklahoma CDL General Knowledge Practice Questions

Try these sample questions to review concepts for the Oklahoma CDL General Knowledge exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 310+ question experience with AI tutoring.

1What is the first step in the seven-step pre-trip inspection method?
A.Approach the vehicle and check its general condition
B.Check under the hood
C.Start the engine and inspect inside the cab
D.Walk around and inspect the entire vehicle
Explanation: The first step of the seven-step pre-trip inspection is to approach the vehicle and look at its general condition. This includes checking for damage, whether the vehicle is leaning to one side, and looking under the vehicle for fresh leaks of oil, coolant, grease, or fuel. This initial overview can immediately reveal serious problems before you invest time in a detailed inspection. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
2During a pre-trip inspection, what should you check in the engine compartment?
A.Only the oil level
B.Oil level, coolant level, power steering fluid, belts, and hoses
C.Only the coolant level and belts
D.Only items visible without opening any caps
Explanation: A thorough engine compartment inspection includes checking the oil level, coolant level in the radiator, power steering fluid, condition of belts and hoses for wear or cracks, and looking for leaks. You should also check the alternator, water pump, air compressor, and any other belt-driven components. Checking only one or two items could mean missing a critical problem that leads to a breakdown or safety hazard on the road. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
3When performing a pre-trip inspection, the driver should ensure that the steering wheel free play (lash) does not exceed what limit?
A.5 degrees in either direction
B.10 degrees in either direction (approximately 2 inches on a 20-inch wheel)
C.15 degrees in either direction
D.20 degrees in either direction
Explanation: Federal Motor Carrier Safety Regulations require that steering wheel free play (lash) not exceed 10 degrees in either direction, which translates to roughly 2 inches of movement on a 20-inch diameter steering wheel before the front wheels begin to turn. Excessive free play indicates worn steering components and can make precise steering difficult, especially in emergency maneuvers. A vehicle with excessive steering lash would be placed out of service. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
4During the cab check portion of a pre-trip inspection, you should test the parking brake by:
A.Driving forward slowly and applying the parking brake
B.Putting the vehicle in gear with the parking brake set and gently pressing the accelerator to see if the vehicle holds
C.Visually checking that the parking brake handle is in the correct position
D.Checking the parking brake cable under the vehicle
Explanation: To properly test the parking brake, set the parking brake, put the vehicle in a low gear, and gently press the accelerator to see if the brake holds the vehicle in place. This functional test confirms the parking brake can actually prevent the vehicle from moving, which is essential for safety when parked on grades. A visual check alone is insufficient because it does not verify that the brake mechanism is actually functioning properly. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
5Which emergency equipment is required to be on a commercial motor vehicle?
A.Fire extinguisher, spare fuses, and three red reflective triangles
B.First aid kit, fire extinguisher, and flares only
C.Fire extinguisher and road flares only
D.Spare tire, jack, and reflective vest
Explanation: Federal regulations require every commercial motor vehicle to carry a properly charged and rated fire extinguisher (minimum 5 B:C rating, or two 4 B:C extinguishers), spare electrical fuses (unless the vehicle has circuit breakers), and three red reflective warning triangles (or equivalent). These items are checked during inspections and roadside enforcement stops. A vehicle missing any of these required items can be cited for a violation. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
6A post-trip inspection report is important because:
A.It is only required for vehicles carrying hazardous materials
B.It alerts the carrier to vehicle defects that may need repair before the vehicle is driven again
C.It replaces the need for the next driver to do a pre-trip inspection
D.It is optional but recommended by the FMCSA
Explanation: The post-trip inspection report (also called a DVIR, or Driver Vehicle Inspection Report) is required by FMCSA regulations (49 CFR 396.11). Its purpose is to document any defects or deficiencies discovered at the end of the trip so the carrier can arrange repairs before the vehicle is dispatched again. The next driver must review the previous post-trip report and verify that any noted defects have been repaired or certified as not needing repair. It does not replace the next driver's pre-trip inspection obligation. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
7During a pre-trip inspection, the driver notices a coolant leak near the water pump. What should the driver do?
A.Note it on the report and drive carefully to the next service stop
B.Add more coolant and continue the trip
C.Do not drive the vehicle until the leak is repaired
D.Drive only short distances and monitor the temperature gauge
Explanation: A coolant leak is a serious defect that can lead to engine overheating and catastrophic engine failure. The vehicle should not be driven until the leak is repaired. Driving with a coolant leak risks engine damage, potential fire (if coolant contacts hot exhaust components), and could result in a roadside breakdown in an unsafe location. FMCSA regulations require that defects affecting safe operation be corrected before the vehicle is driven. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
8Which of the following is an out-of-service condition that would prevent a vehicle from being driven?
A.A small crack in the windshield that does not obstruct the driver's view
B.A missing mud flap on a rear wheel
C.Brake lining thickness below the minimum allowed by regulations
D.A broken antenna on the CB radio
Explanation: Brake lining worn below the minimum thickness specified in FMCSA out-of-service criteria is a critical safety defect. The North American Standard Out-of-Service Criteria lists specific thresholds: brake lining must not be less than 1/4 inch thick at the thinnest point for air-braked vehicles. When brake linings are too thin, braking effectiveness is severely compromised, and the vehicle must be placed out of service until repairs are made. A small windshield crack not in the driver's view, a missing mud flap, or a broken CB antenna are defects but not typically out-of-service conditions. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
9During the pre-trip inspection, which of the following should a driver check regarding the exhaust system?
A.Only that the muffler is present
B.That the exhaust system is secure, not leaking, and not in contact with fuel lines, wiring, or air lines
C.Only that exhaust fumes are not entering the cab
D.That the catalytic converter is functioning properly by checking emissions color
Explanation: When inspecting the exhaust system, the driver should verify that all components are properly mounted and secured, there are no leaks (which could allow poisonous carbon monoxide to enter the cab), and the exhaust system is not in contact with fuel supply lines, wiring, or air brake lines. Heat from the exhaust can damage these components, potentially causing fuel leaks, electrical fires, or brake failures. A complete exhaust system inspection goes beyond just checking for the presence of a muffler. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.
10What is the minimum tread depth required for steer axle tires on a commercial motor vehicle?
A.2/32 of an inch
B.4/32 of an inch
C.6/32 of an inch
D.1/32 of an inch
Explanation: Federal regulations require steer axle tires to have a minimum tread depth of 4/32 of an inch (approximately 3.2 mm) in every major groove. Steer tires have a higher minimum than other axle positions (which require only 2/32 of an inch) because the steer tires are critical for directional control of the vehicle. Tires below this minimum are considered unsafe and will result in a violation or out-of-service order during an inspection. This aligns with the Oklahoma Commercial Driver License Manual general-knowledge material and FMCSA CDL testing standards used by state driver licensing agencies.

About the Oklahoma CDL General Knowledge Exam

The Oklahoma CDL General Knowledge Test is the base written knowledge exam for Oklahoma commercial learner permit and commercial driver license applicants. Service Oklahoma directs applicants to study the official CDL Driver Manual, which covers general knowledge for all CDL applicants and separate class or endorsement material when applicable. FMCSA requires each basic CDL knowledge test to cover the 20 general areas in 49 CFR 383.111(a), contain at least 30 items, and require at least 80% correct to pass. The test emphasizes safe commercial motor vehicle operation: inspection, basic control, shifting, speed and space management, seeing and communication, adverse conditions, emergencies and skids, cargo securement, driver wellness and fatigue, alcohol and drug rules, and CDL licensing basics.

Exam sponsor: Service Oklahoma. The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

Multiple-choice CDL knowledge test covering the basic general-knowledge areas required for commercial motor vehicle operators; air brakes, combination vehicles, and endorsements may require separate tests depending on the license sought.

Time Limit

Not published by Service Oklahoma or FMCSA for the General Knowledge test

Passing Score

At least 80% correct on each CDL knowledge test

Exam / Certification Fees

$25 for one ServiceOK/CareerTech CDL written exam session; $30 for two exams, $35 for three, or $40 for four exams; credential fees vary by class and term

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

Core general-knowledge area

Vehicle Inspection

Pre-trip, en-route, and post-trip checks; safety-critical components; emergency equipment; tires, brakes, lights, mirrors, and cargo checks.

Core general-knowledge area

Basic Vehicle Control and Mountain Driving

Starting, steering, backing, turning, off-tracking, shifting, braking, curves, downgrades, and controlling a large commercial motor vehicle.

Core general-knowledge area

Speed, Space, Seeing, and Communication

Following distance, stopping distance, overhead clearance, turns, merging gaps, railroad crossings, mirror use, signaling, and hazard perception.

Core general-knowledge area

Night, Weather, Hazards, Emergencies, and Skids

Night visibility, fog, rain, hydroplaning, snow, ice, blowouts, skids, fires, crash response, escape ramps, and fatigue prevention.

Core general-knowledge area

Cargo Securement and Weight

Blocking and bracing, tie-down basics, cargo inspection intervals, sealed loads, weight distribution, and axle/GVW awareness.

Core general-knowledge area

FMCSA and Oklahoma CDL Basics

CDL classes, CLP/CDL application basics, medical certification, ELDT, drug and alcohol rules, disqualifications, Oklahoma fees, and Service Oklahoma procedures.

Preparing for the Oklahoma CDL General Knowledge Exam

What You Need to Know

  • Passing score: At least 80% correct on each CDL knowledge test
  • Assessment: Multiple-choice CDL knowledge test covering the basic general-knowledge areas required for commercial motor vehicle operators; air brakes, combination vehicles, and endorsements may require separate tests depending on the license sought.
  • Time limit: Not published by Service Oklahoma or FMCSA for the General Knowledge test
  • Exam / certification fees: $25 for one ServiceOK/CareerTech CDL written exam session; $30 for two exams, $35 for three, or $40 for four exams; credential fees vary by class and term Official sources

Using Our Practice Resources

  • Work through all 310 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

Oklahoma CDL General Knowledge: Suggested Study Strategy

1Read the Service Oklahoma CDL Driver Manual before drilling practice questions; Oklahoma testing is based on the state manual covering topics from FMCSA standards.
2Master pre-trip inspection language: know what to inspect, why it matters, and what defects make a vehicle unsafe.
3Practice speed and space rules until following distance, stopping distance, clearance, and railroad-crossing decisions are automatic.
4Separate General Knowledge from endorsements: add air-brake, combination-vehicle, hazmat, passenger, school bus, tanker, or doubles/triples prep only when your CDL path requires those tests.
5Review missed questions by topic and return to the corresponding manual section instead of memorizing only the answer text.
6Confirm current testing location procedures, fees, medical-card requirements, and ELDT status on Service Oklahoma pages before visiting an exam site.

Frequently Asked Questions

Who administers the Oklahoma CDL General Knowledge Test?

Service Oklahoma administers Oklahoma CDL licensing and written testing. Some ServiceOK CDL written exams are also offered through Oklahoma CareerTech testing centers as a proctored ServiceOK testing option.

How many questions are on the Oklahoma CDL General Knowledge Test?

FMCSA requires each basic CDL knowledge test to contain at least 30 items. Service Oklahoma does not publish a separate public item count for the General Knowledge form, so use the federal minimum as the traceable baseline.

What score do I need to pass?

FMCSA requires CDL applicants to correctly answer at least 80% of the questions on each CDL knowledge test. That 80% rule applies to general and endorsement knowledge tests.

How much does Oklahoma CDL written testing cost?

Oklahoma CareerTech lists ServiceOK CDL written testing fees of $25 for one exam in a session, $30 for two exams, $35 for three exams, and $40 for four exams. Service Oklahoma also lists an additional $4.00 charge added to the licensing fee for retests.

What should I study for Oklahoma CDL General Knowledge?

Study the Service Oklahoma CDL Driver Manual, especially general-knowledge content on vehicle inspection, basic control, shifting, speed and space, seeing and communication, adverse conditions, emergencies, cargo, fatigue, alcohol and drug rules, and CDL licensing requirements.

Do I need separate tests for air brakes, combination vehicles, or endorsements?

Yes, depending on the vehicle and license you want. Service Oklahoma notes that the CDL manual includes class and endorsement tests separate from general knowledge, and the endorsements page identifies separate study sections for hazmat, passenger, school bus, tanker, doubles/triples, and air brakes.