Petrol vs Diesel vs CNG Car: Key Differences
The Indian automobile market is known for its budget-friendly, value-for-money, and fuel-efficient cars. The Indian buyer sentiment is such that mileage or fuel economy always takes the front seat when buying a new car. Hence, fuel-efficient CNG, petrol or diesel cars are popular in India. But which car is best for you? To answer this question, you need to understand the key differences between diesel, petrol, and CNG cars.
Glance through the table below to better understand petrol vs diesel vs CNG cars.
Note: The below comparison assumes that the cars have similar engine capacity (cc) and belong to the same segment.
| Parameters | Petrol car | Diesel car | CNG Car |
| Fuel price | High | Lower than petrol | Low |
| Car price | More affordable than diesel and CNG cars. | More expensive than petrol and CNG cars. | More expensive than petrol cars, but affordable compared to diesel cars. |
| Performance | It offers good performance with better pickup than diesel and CNG cars. | Slower initial acceleration but offers good top-end performance. | Lower power output than petrol and diesel cars. Also, you may experience a slight lag in power delivery. |
| Comfort | Petrol engines are refined, and the NVH (Noise, Vibration, Harshness) levels are low inside the car. Hence, they offer a comfortable driving experience. | Diesel engines are less refined than petrol engines. Hence, the NVH levels are higher inside the cabin. | Since CNG cars run on petrol-compatible engines, the refinement is on par with petrol cars. |
| Boot space | Spacious | Spacious | It is non-existent since the CNG fuel tank eats up the boot space, which may not be practical for long drives. |
| Mileage | Lower than CNG and diesel cars. | Higher than petrol cars, but lower than CNG cars. | Higher than petrol and diesel cars. |
| Running cost | High | Lower than petrol cars, but higher than CNG cars. | Low |
| Maintenance cost | Higher than CNG cars but lower than diesel cars. | High | Higher than petrol and diesel cars due to the fitment of a CNG kit. |
| Environmental friendliness | It is not environment-friendly as the exhaust gas comprises carbon monoxide. | It produces carbon emissions. | They are environment-friendly as the fuel is completely combustible and produces clean emissions. |
| Fuel availability | Easily available | Easily available | CNG fuel stations are not as easily available as petrol or diesel fuel stations. |
| Engine life | Lower than diesel engines. | Diesel engines last longer than petrol engines. | The engine life is similar to that of petrol engines. |
CNG vs Petrol vs Diesel Mileage
CNG cars are the most fuel-efficient out of the three fuel types of cars. In contrast, diesel cars offer better fuel economy than petrol cars. However, they cannot match the mileage of CNG cars. Petrol cars are the least fuel-efficient. However, the fuel efficiency depends on your driving style. For instance, if you drive a diesel car aggressively, you cannot expect good fuel economy.
CNG vs Petrol vs Diesel Engine Life
When it comes to engine life in petrol vs diesel cars vs CNG vehicles, diesel cars take the honour. A diesel engine lasts longer than petrol and CNG-powered engines. That’s mainly due to diesel’s fuel properties. Diesel is a volatile fuel, and it also lubricates the engine components. Hence, a diesel engine will last longer than its petrol and CNG counterparts.
Petrol and CNG engines have similar engine life, which is less than that of diesel engines. One common myth related to CNG cars is that CNG fuel reduces engine life. But in reality, it is not the case. CNG fuel does not damage the engine components despite having different fuel properties than petrol/diesel. Hence, petrol and CNG engines have a similar life.
CNG vs Petrol vs Diesel Car Maintenance
Petrol engine cars are cheaper to maintain as the engine spare parts are affordable. On the contrary, diesel engines have complex components. Hence, the spare parts price also goes up. Overall, diesel cars are more expensive to maintain than petrol cars.
CNG cars run on bi-fuel petrol engines. That means you can drive the car with petrol or CNG fuel. Now the maintenance costs are similar to those of petrol cars. But it’s not the case here. Since a CNG car has a CNG kit and an engine, the maintenance costs are high. The maintenance cost of a CNG car also depends on the quality of the kit. They also require frequent checks to identify any leaks in the system. Hence, the overall maintenance costs can run high, even higher than petrol and diesel cars, if the vehicle is not maintained correctly.
Resale Value Considerations
CNG cars tend to fetch a lower resale price than petrol and diesel cars. Major drivers of this are restricted demand from buyers and doubts over CNG infrastructure. Petrol cars tend to have a better resale price situation, especially where the petrol infrastructure is strong. Their popularity all around and reliability lead to uniform demand in the second-hand car market.
Environmental concerns and policy adjustments can influence the resale value of petrol vs diesel car. For instance, restrictions like the ban on diesel cars in certain cities for 10 years have influenced demand in the long term.
Safety Aspects
CNG is safer as it has a higher auto-ignition temperature of approximately 540°C compared to petrol with 280°C. CNG is not prone to catching fire if left on hot surfaces. Additionally, in a leakage, CNG disperses instantly into the air and reduces the chances of a fire hazard.
In the case of a petrol vs diesel car, while generally both are safe, petrol and diesel fuel are less secure due to lower auto-ignition temperatures and thus are more flammable. This requires stricter security measures in a bid to prevent accidents.
Infrastructure and Availability
There are nearly no CNG refilling stations in some places, and that creates humongous lines and trouble for the commuters. For example, in Bhopal, with about 35 CNG refilling stations, there are physical constraints and operational inefficiencies that cause refilling to take over 30 minutes.
Petrol and diesel fuels are easily found throughout the country, and it is simple to refuel, one finds. With numerous fueling stations scattered here and there, drivers consider it convenient to purchase this kind of fuel, reducing shortage problems when driving long distances.
Government Regulations and Emission Norms
In order to meet Bharat Stage VI (BS6) emission standards, diesel cars require major technological upgradations such as the use of diesel particulate filters and selective catalytic reduction units. The upgradations have raised the price and sophistication of diesel cars. Petrol cars were also brought to BS6 specifications, such as the application of sophisticated fuel injection systems and catalytic converters. But the process was relatively costlier and easier for petrol cars compared to diesel cars.
CNG vehicles naturally emit pollutants in lesser quantities, which is absolutely in accordance with BS6 standards. They release lower nitrogen oxides and particulate matter through their green burning mechanism, and thus, they are environmentally friendly.
Petrol vs Diesel Car, Which is Better
Now, you know the advantages and disadvantages of petrol and diesel cars. So, which one makes a better choice for a petrol car vs diesel car The answer to this question depends on your driving requirements.
If you need a car for long-term usage, and your average driving distance is on the higher side, a diesel car might be a sensible choice. On the other hand, if you plan to upgrade your car in a few years, and your average driving distance is significantly less, then you can go for a petrol car.
CNG car vs Petrol Car, Which is Better
The next question on your mind would be, which is a better choice in terms of CNG vs petrol car Since both types of cars run on petrol engines, it may be a tricky choice. But to make it simpler, let’s put it this way. If you need a daily driver car, a CNG car makes a lot of sense. A petrol car will be a good choice if you need a car for daily commutes and long drives.
Conclusion
There is no specific answer to the question: Which is better, a diesel or a petrol car? Or a CNG car? Because the choice depends on your requirements. Below are some key points to consider when deciding on the car's fuel type.
- If you are looking for a car with overall good performance, can munch miles easily, and lasts long, diesel cars are best for you.
- If you wish to own a car that is low maintenance and has enough grunt under the bonnet, petrol cars are the best.
- Lastly, CNG cars are the way to go if you need a vehicle for daily commutes with low running costs. Plus, CNG cars are also eco-friendly. Hence, you do not pollute the environment when driving a CNG car.
Frequently Asked Questions
