How To Maintain A CNG Car In India For Better Mileage & Safety

With the rise of fuel prices and growing environmental concerns, more Indian car owners are turning to CNG vehicles for their cost efficiency and cleaner emissions. Compressed Natural Gas (CNG) cars offer significant savings on running costs compared to petrol or diesel vehicles, but they demand specific maintenance practices to stay efficient, safe, and long-lasting. According to automotive experts, following a disciplined maintenance routine can help retain a CNG car’s performance, enhance mileage, and ensure consistent safety on Indian roads.
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Understanding the Needs of a CNG Car

CNG cars differ mechanically from petrol or diesel vehicles because they rely on high-pressure natural gas stored in cylinders. This system requires regular inspection to prevent leaks or pressure loss. The combustion process in CNG engines also generates less carbon residue, meaning less oil contamination but greater dependence on correct tuning and air-fuel balance. Therefore, preventive care plays a more crucial role than reactive repairs when maintaining a CNG car.

Experts emphasise that neglecting routine checks may result in reduced power output, irregular mileage, and potential safety risks. A well-maintained CNG system ensures not just performance but also compliance with emission norms and longer engine life.


Regular Inspection of the CNG Kit

The CNG kit is the heart of the vehicle, and its condition directly affects the car’s mileage and performance. Owners should have the kit inspected by authorised service centres every six months or after every 10,000 kilometres, whichever comes first. Service checks should include pressure regulators, valves, filters, and the cylinder’s structural integrity.

A common issue with older CNG cars is gas leakage from worn-out seals or joints. Even small leaks can lead to reduced mileage and pose fire hazards. As per expert recommendations, cylinders should undergo hydro testing every three years at a government-approved testing facility. This ensures that the cylinder can safely hold the gas pressure.


Engine Oil and Spark Plug Maintenance

CNG fuel burns cleaner than petrol, leading to less carbon deposit in the engine. However, it also burns at a higher temperature, which can cause faster wear on spark plugs and engine valves. To offset this, experts recommend using engine oils formulated specifically for CNG vehicles, as they offer higher thermal resistance and reduced ash content.

Spark plugs should also be checked or replaced more frequently than in petrol cars — typically every 15,000 to 20,000 kilometres. Using the manufacturer-specified spark plugs with the correct gap setting is vital to maintaining smooth ignition and efficient combustion.

Maintaining Optimum Tyre Pressure and Air Filters

Tyre pressure plays a key role in maintaining mileage, especially in CNG vehicles where power output is slightly lower than petrol engines. Under-inflated tyres increase rolling resistance, reducing fuel efficiency. Checking tyre pressure weekly and maintaining the manufacturer’s recommended PSI can improve mileage significantly.

Similarly, the air filter should be cleaned or replaced regularly. Because CNG engines rely on the precise air-to-fuel ratio, a clogged air filter can upset combustion balance, resulting in sluggish performance or poor fuel economy. Replacing air filters every 10,000 kilometres ensures consistent airflow and cleaner combustion.


Balancing Performance and Safety

Apart from performance, safety is equally crucial. Always switch off the ignition when refuelling a CNG car, and never smoke near the filling station. Make sure the gas cap is sealed tightly after refuelling. Experts also caution against parking CNG cars under direct sunlight for prolonged periods, as high heat can affect gas pressure inside the cylinder.

Routine inspections of CNG pipelines and joints should be done to detect any signs of wear or corrosion. If the car emits a distinct odour of gas, it should be taken immediately to an authorised service centre instead of a local garage. CNG systems are high-pressure setups, and untrained handling can compromise safety.

Driving Habits that Protect the Engine

Smooth driving habits can extend the life of a CNG car. Avoid frequent hard acceleration and sudden braking, as this puts pressure on both the engine and transmission. Since CNG cars generally deliver better mileage on steady speeds, maintaining moderate acceleration improves performance.

Experts also suggest starting the car on petrol and switching to CNG after one or two minutes of running. This allows the engine to reach optimum temperature and ensures smooth transition between fuels. Similarly, before switching off the car, it is advisable to revert to petrol mode for a short while to prevent dryness in valves and injectors.

When to Seek Professional Help

DIY maintenance can cover basic checks, but professional servicing remains essential. If you notice reduced pick-up, hissing sounds near the engine bay, or a sudden drop in mileage, get the car examined by trained CNG technicians. Using unapproved CNG components or refilling at uncertified outlets can lead to serious safety risks.


By adhering to these expert-approved practices, Indian car owners can ensure that their CNG vehicles remain cost-efficient, reliable, and safe over long use.

Disclaimer: This article is intended for informational purposes only. Readers are advised to consult qualified automotive professionals or authorised CNG service centres for accurate guidance on maintenance and safety procedures.