Which Car Is Best - Petrol Or Diesel?

When a person sets out to buy a car, a common question they may think of is - should I buy a petrol car or a diesel car? Each fuel type has its pros and cons, whether it is fuel efficiency or maintenance costs. As new technology and environmental awareness come to the fore, the decision to choose the right fuel type has become even more important. One thing common between diesel and petrol cars is the need for car insurance. It is mandatory as per prevailing laws (third-party insurance coverage), and also helps the car-owner have better peace of mind.* Claims are subject to terms and conditions set forth under motor insurance policy. While car insurance is a common ground between petrol and diesel cars, when it comes to the vehicles themselves, there are multiple differences.

Key Differences between a Petrol and a Diesel Car 

To get an overview of the main differences between both types of cars, let’s look at the following points:

1. Price - Petrol cars are usually more affordable when compared to their diesel counterparts.
2. Service and maintenance - The cost of service and maintenance tends to be lower for petrol cars, while diesel cars may incur relatively higher expenses in those regards.
3. Fuel efficiency/mileage - Petrol cars typically offer lower fuel efficiency than their diesel counterparts.
4. Refinement - Petrol cars exhibit lower NVH (Noise, Vibration, and Harshness) levels, leading to a quieter driving experience. Diesel cars, on the other hand, can have higher NVH levels.
5. Power - Petrol cars provide good initial acceleration with linear power delivery. Diesel cars are better at pulling power due to the increased torque.
6. Eco-friendliness - Petrol engines produce fewer pollutants, making them less harmful to the environment. Diesel engines emit more pollutant particulate matter, which may make them less eco-friendly.
7. Engine life - Petrol engines generally have a shorter lifespan due to fuel properties causing quicker wear and tear. Diesel engines, however, tend to last longer with less pronounced wear and tear.
8. Fuel price - Petrol is typically more expensive than diesel, making the latter a comparatively more cost-effective fuel option.
9. Resale value - Petrol cars usually have a lower resale value, while diesel cars often command a higher resale value as compared to their petrol counterparts.

The above points can help one decide which car (petrol or diesel) is best to a certain extent. However, let’s delve a bit deeper by looking at the differences between a petrol engine and a diesel engine.

Petrol Engine Vs Diesel Engine - A Basic Comparison

Both types of engines are internal combustion engines - that is, they turn the chemical energy of fuels into mechanical energy to run the vehicle. However, there are differences between both:  

Parameters	Petrol engine	Diesel engine
Working principle	The Otto cycle	The diesel cycle
Air-fuel mixture	Air and fuel mixture happens prior to the compression.	The mixture happens inside the combustion chamber.
Ignition of fuel	Fuel ignition occurs due to a spark produced through the spark plugs.	Fuel ignition happens due to the hot compressed air.
Compression ratio	Low	High
Power	Less than that of a diesel engine.	Comparatively higher than petrol engines.
Fuel	High volatile fuels, such as petrol.	Diesel, which is a low-volatile fuel.
Application	Mostly two-wheelers and cars, or other light vehicles.	SUVs and heavy vehicles, such as trucks and buses.
Fuel economy	Low	High
Cost of maintenance	Low	High

 

Petrol car vs Diesel Car - Fuel Cost, Efficiency and Pricing 

Now, let’s explore the comparison between petrol cars and diesel cars by looking at the fuel cost and efficiency of each type of car. We will take the Tata Nexon (Manual) as an example, which is available in petrol and diesel variants. Let’s look at the ARAI (Automotive Research Association of India)-claimed mileage of each car:

1. Tata Nexon Diesel variant - 23.23 kmpl
2. Tata Nexon Petrol Variant - 17.4 kmpl.

Now, let’s calculate the monthly fuel cost based on the following:

1. Kms driven in a day - 50 kms.
2. Average price of diesel - ₹93/litre.
3. Average price of petrol - ₹106/ litre.

Thus, taking the mileage of the diesel variant as 23.23 kmpl, the monthly fuel cost for it would be ₹6065. And, taking the mileage of the petrol variant as 17.4 kmpl, the monthly fuel cost for it would be ₹9353. Thus, when comparing which car is better, petrol or diesel, in terms of fuel efficiency, the diesel variant may be a better option. However, diesel cars can cost more. For instance, the Delhi ex-showroom price of the Nexon Creative Petrol variant is ₹12.70 lakhs, while its diesel variant is priced at ₹14.60 lakhs. Once you have chosen the right fuel option, remember to secure it with the right motor insurance plan that provides the coverage you need within your budget.* Claims are subject to terms and conditions set forth under motor insurance policy.   * Standard T&C apply. Insurance is the subject matter of solicitation. For more details on benefits, exclusions, limitations, terms, and conditions, please read the sales brochure/policy wording carefully before concluding a sale.