CNG Car Safety and Maintenance Guide: Precautions, Tips

Compressed Natural Gas (CNG) vehicles have gained popularity as an economical and environmentally friendly alternative to conventional petrol and diesel cars. With rising fuel costs and growing environmental concerns, CNG has emerged as a viable solution for cost-conscious and eco-aware drivers. However, maintaining a CNG vehicle requires specific knowledge and care to ensure optimal performance and longevity. This comprehensive guide aims to equip CNG car owners with essential maintenance practices, safety protocols, and insurance considerations to maximise their vehicle's lifespan while ensuring reliable operation on the road.

What is a CNG Filter and Why is it Important?

A CNG filter is a critical component of the CNG fuel system that prevents contaminants from entering the engine and other vital parts of the fuel delivery system. Similar to petrol filters, CNG filters trap impurities, moisture, and particulate matter present in compressed natural gas before it reaches the engine's combustion chamber. Regular maintenance of the CNG filter is essential because natural gas, despite being cleaner than conventional fuels, still contains impurities and moisture that can damage expensive components like injectors and regulators. 

A clogged or inefficient CNG filter can lead to reduced fuel efficiency, decreased engine performance, erratic idling, and in severe cases, complete system failure requiring costly repairs. Experts recommend replacing CNG filters every 20,000-25,000 kilometres to maintain optimal engine health and performance.

CNG Car Safety and Maintenance: Step-by-Step Guidance

Regular CNG Kit Inspection

• Schedule professional inspections every three months or 10,000 kilometres, whichever comes first
• Check for gas leakage regularly by applying a soap and water solution to connections and watching for bubbles
• Inspect all hoses and pipes for cracks, wear, or loose connections that might lead to gas leakage
• Look for corrosion or damage on the CNG cylinder and mounting brackets
• Verify that all electrical connections related to the CNG system are secure and free from corrosion
• Ensure the CNG cylinder valve is functioning properly without any signs of sticking or difficulty in operation

CNG Certificate and Compliance

• Maintain valid CNG certification documents in your vehicle at all times
• Renew your CNG fitness certificate every five years as mandated by transportation authorities
• Schedule hydrostatic testing of the CNG cylinder at authorised testing stations when due
• Keep a record of all maintenance services performed on your CNG system for certification purposes
• Display CNG stickers on your vehicle's front and rear windscreen as required by regulations
• Ensure all modifications to your CNG system are done by authorised service centres only

Engine and Performance Maintenance

• Change engine oil more frequently than for petrol-only vehicles (every 5,000-6,000 kilometres recommended)
• Replace spark plugs at shorter intervals as CNG burns hotter than petrol, causing faster electrode wear
• Clean or replace air filters regularly, as they directly affect the air-fuel mixture and engine performance
• Check and maintain proper valve clearances, as CNG operation can affect valve functioning
• Monitor engine coolant levels diligently, as CNG engines tend to run hotter than petrol engines
• Consider valve seat recession inspection at 50,000 kilometres, particularly for older vehicles

CNG Filter and Fuel System Care

• Replace the CNG filter every 20,000-25,000 kilometres to prevent system contamination
• Clean the CNG injectors periodically to ensure proper fuel atomisation and combustion
• Check the CNG pressure regulator function during regular service appointments
• Inspect fuel lines for any signs of wear, cracks, or potential leak points
• Ensure proper adjustment of the CNG-petrol switch mechanism for smooth transition between fuels
• Test the fuel gauge accuracy for both petrol and CNG tanks regularly

CNG Cylinder Maintenance

• Schedule mandatory hydrostatic testing every five years at authorised testing centres
• Inspect cylinder mounting brackets regularly for looseness or corrosion
• Avoid completely emptying the CNG cylinder frequently, as it can allow moisture to enter the system
• Check cylinder valves and pressure release devices during professional inspections
• Keep cylinder registration and testing certificates updated and available in the vehicle
• Ensure the cylinder installation angle meets manufacturer's specifications

Safety Protocols

• Never attempt DIY repairs on any component of the CNG system
• Immediately address any unusual smell that might indicate a gas leak
• Park in well-ventilated areas whenever possible
• During accidents, inform emergency responders about the CNG installation in your vehicle
• Switch to petrol before entering enclosed underground parking with poor ventilation
• Turn off the CNG supply when parking for extended periods

Also Read: CNG Car Vs Petrol Car: What's The Difference?

Tips to Maintain Your CNG Car

Optimising Fuel Efficiency

• Maintain proper tyre pressure as specified by the manufacturer to reduce rolling resistance and improve fuel economy
• Use the recommended grade of engine oil specifically suitable for CNG/bi-fuel vehicles
• Practice gentle acceleration rather than sudden throttle inputs to maximise CNG efficiency
• Minimise excessive idling as it wastes fuel without serving any purpose
• Plan your refuelling strategically to avoid running on near-empty CNG tanks
• Use petrol occasionally, even if you primarily run on CNG, to keep the petrol system in good working condition
• Keep your vehicle's weight optimised by removing unnecessary items from the boot
• Consider aerodynamic improvements like removing roof racks when not in use
• Drive at steady speeds rather than frequently accelerating and decelerating

Understanding CNG-Petrol Switching

• Switch to petrol mode when starting the car in an extremely cold conditions
• Allow the engine to warm up before switching from petrol to CNG mode
• Avoid switching from CNG to petrol while accelerating hard
• Periodically run the car on petrol for at least 20-30 kilometres to keep the petrol system functional
• Refill your petrol tank regularly, even if you primarily use CNG, to prevent moisture accumulation
• Monitor for smooth transitions between fuel types, addressing any roughness immediately
• Understand the fuel-switching sequence recommended by your car manufacturer

Prolonging CNG Kit Lifespan

• Choose high-quality CNG kits from reputable manufacturers with proper certification
• Ensure installation by authorised and experienced technicians only
• Follow manufacturer-recommended service intervals without delays
• Use dust covers on CNG filling receptacles when not in use to prevent contamination
• Protect the CNG ECU from water exposure and electrical system fluctuations
• Keep service records to track component replacements and maintenance history
• Consider sequential CNG kits for newer vehicles, as they provide better performance and longevity

Addressing CNG-Specific Issues

• Monitor for excessive water in the system by checking moisture traps regularly
• Listen for unusual sounds when operating on CNG, which may indicate problems
• Address any power loss immediately, as it could indicate filter clogging or regulator issues
• Check for leaks after every major service or repair work on the vehicle
• Monitor mileage consistently to detect early signs of efficiency loss
• Have specialised diagnostics performed if you notice any performance issues
• Keep emergency contacts of CNG service centres handy for roadside assistance

Professional Maintenance Schedule

• First major CNG system service at 10,000 kilometres after installation
• Regular CNG tune-ups every 20,000 kilometres or as recommended by the manufacturer
• Complete system overhaul every 100,000 kilometres, including regulator rebuilding
• Annual leak testing using electronic gas leak detectors at professional service centres
• Bi-annual emissions testing to ensure environmental compliance
• Schedule preventive maintenance before long road trips to avoid breakdowns
• Maintain coordination between regular car service and CNG kit service schedules

Insurance and Documentation

• Purchase specialised CNG car insurance that covers the CNG kit and cylinder explicitly
• Declare CNG modifications to your insurer to avoid claim rejection in case of accidents
• Keep installation certificates and receipts safe for insurance and regulatory purposes
• Renew cylinder testing certificates before expiry to maintain insurance validity
• Consider roadside assistance coverage specifically for CNG vehicles from providers like Bajaj Allianz General Insurance Company
• Document all professional inspections with service reports for future reference

Also Read: Everything You Need to Know About CNG

CNG Car Insurance: What You Must Know?

Insuring a CNG-fitted vehicle requires special consideration since standard car insurance policies may not fully cover the CNG kit and cylinder. When purchasing insurance for your CNG car, explicitly declare the CNG modification to ensure comprehensive coverage. Bajaj Allianz General Insurance Company offers specialised policies that cover not only your vehicle but also the CNG kit installation, providing protection against damage, theft, or loss. 

Their motor insurance includes access to their network of 7,200+ cashless garages, many of which are equipped to handle CNG vehicles, ensuring hassle-free claims processing and repairs by trained technicians who understand the complexities of CNG systems. Remember that failing to disclose CNG modifications to your insurer could result in claim rejection, making proper declaration essential for complete protection.

Conclusion

Maintaining a CNG vehicle requires attentiveness to specific components and adherence to regular service schedules that differ from conventional petrol cars. While this might seem demanding, the economic and environmental benefits of CNG vehicles make these additional maintenance efforts worthwhile. 

By following the guidelines outlined in this comprehensive maintenance guide, you can ensure optimal performance, enhanced safety, and extended longevity of your CNG car. Remember that professional expertise is crucial for CNG system maintenance, so establish a relationship with authorised service centres and consider comprehensive insurance coverage from Bajaj Allianz General Insurance Company to protect your investment for years to come.

FAQs

What if my CNG car runs out of gas while driving?

If your CNG car runs out of gas while driving, it will automatically switch to petrol mode if you have a bi-fuel system. Ensure you maintain some petrol in the tank as a backup. Modern CNG cars usually have a warning indicator that lights up when CNG levels are low. If your car doesn't switch automatically, use the manual fuel selector switch to change to petrol mode and proceed to the nearest CNG station.

Does installing a CNG kit damage my car's engine?

A properly installed, high-quality CNG kit by certified technicians won't damage your engine. CNG burns cleaner than petrol, resulting in less carbon build-up and potentially longer engine life. However, poor installation or low-quality kits can cause issues like reduced power, valve seat recession, and increased wear. Regular maintenance of both the engine and CNG system is essential to prevent potential damage.

Why are CNG cars not so popular in India?

Despite economic benefits, CNG cars face challenges in India, including limited refuelling infrastructure outside major cities, longer refuelling times compared to petrol/diesel, reduced boot space due to cylinder installation, and higher initial investment costs. Additionally, waiting times at CNG stations during peak hours and concerns about CNG kit reliability and maintenance have hindered widespread adoption, though popularity is steadily increasing in regions with good CNG infrastructure.

Do I have to get out of the car while refuelling CNG?

Yes, passengers must exit the vehicle during CNG refuelling as a safety precaution. This is mandatory at all CNG stations to minimise risk in case of gas leakage or other emergencies. Additionally, the engine must be switched off, mobile phones shouldn't be used, and smoking is strictly prohibited in the refuelling area. These safety protocols are legal requirements and are enforced at all authorised CNG stations.

Which are the best CNG cars in India?

The top CNG cars in India include the Maruti Suzuki Wagon R, known for excellent mileage and reliability; Maruti Suzuki Ertiga, popular for family use with factory-fitted CNG; Hyundai Grand i10 Nios, offering refined driving experience with factory CNG; Tata Tiago iCNG with advanced safety features; and Honda Amaze CNG, providing sedan comfort with economical running costs. Factory-fitted CNG models generally offer better integration and reliability than aftermarket installations.

Which is the best time to refuel a CNG car?

Early mornings or late evenings are ideal for CNG refuelling as stations are less crowded, resulting in shorter queues and faster service. During cooler temperatures, you may get slightly better gas filling due to higher density of compressed gas. Avoid peak hours (8-10 AM and 5-7 PM) when commuter traffic creates long waiting times. Also, refuel before the gauge shows reserve levels to prevent complete depletion and potential moisture intake.

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