CNG CNG Fleet Management and Driver Operations 1 — Questions and Answers
Question 1: Before fueling a CNG vehicle, a driver should first verify which condition?
- The vehicle engine is turned off (Correct answer)
- The fuel tank is completely empty
- The dispensing nozzle is at maximum pressure
- The vehicle is in drive gear
Correct answer: The vehicle engine is turned off
Drivers must always turn off the engine before fueling a CNG vehicle to prevent ignition of any gas released during nozzle connection.
Question 2: What does a CNG vehicle's fuel gauge reading in GGE allow fleet managers to determine?
- Estimated driving range compared to an equivalent gasoline vehicle (Correct answer)
- The cylinder burst pressure rating
- The number of cylinders installed
- Current ambient temperature compensation
Correct answer: Estimated driving range compared to an equivalent gasoline vehicle
Displaying fuel in GGE lets drivers and fleet managers estimate range using familiar gasoline consumption benchmarks.
Question 3: Which pre-trip inspection item is unique to CNG vehicles that gasoline vehicle drivers do not need to perform?
- Visual inspection of CNG cylinders and fuel lines for damage or leaks (Correct answer)
- Checking tire pressure
- Inspecting windshield wipers
- Verifying brake fluid level
Correct answer: Visual inspection of CNG cylinders and fuel lines for damage or leaks
CNG drivers must visually inspect high-pressure cylinders and fuel lines for cracks, corrosion, or signs of leakage before each trip.
Question 4: If a CNG driver smells natural gas inside the vehicle cab while driving, what is the correct immediate action?
- Pull over safely, turn off the engine, exit the vehicle, and call for assistance (Correct answer)
- Accelerate to ventilate the cab with airflow
- Turn on the air conditioning recirculation mode
- Continue driving to the nearest service station
Correct answer: Pull over safely, turn off the engine, exit the vehicle, and call for assistance
A gas odor in the cab indicates a potential leak; the driver must stop immediately, shut off the engine, and evacuate to prevent ignition.
Question 5: Which document must CNG commercial vehicle operators carry to comply with DOT Hazardous Materials Regulations when transporting CNG as cargo?
- Shipping papers describing the compressed natural gas per 49 CFR Part 172 (Correct answer)
- A state driver's license only
- An EPA emissions certificate
- A NFPA 52 inspection sticker
Correct answer: Shipping papers describing the compressed natural gas per 49 CFR Part 172
DOT requires shipping papers describing hazardous materials (including compressed natural gas) when transported as cargo, per 49 CFR Part 172.
Question 6: What is the purpose of a CNG vehicle's manual fuel shutoff valve, and when should a driver use it?
- It stops fuel flow from the cylinder in an emergency or during maintenance (Correct answer)
- It increases fuel pressure to the engine for better performance
- It resets the fuel gauge to full
- It vents excess pressure to the atmosphere automatically
Correct answer: It stops fuel flow from the cylinder in an emergency or during maintenance
The manual shutoff valve isolates the CNG cylinder from the fuel system and should be closed during emergencies, accidents, or maintenance.
CNG CNG Fleet Management and Driver Operations 1
Before fueling a CNG vehicle, a driver should first verify which condition?