Just 10 years ago, 58% of passenger cars sold in India were diesel; In 2022, this number will be only 18%. Indian car buyers are gradually moving away from diesel engines. One of the reasons for this decline is the reduction in the price differential between the two fuels – a petrol vs diesel car– from Rs 20 to 25 in 2013 to around Rs 7 to 10 per litre today.
Should you consider a diesel car today?
Petrol vs diesel car: what are the advantages of each type of fuel? We get to the bottom of these and other questions by comparing three popular diesel cars in India with their petrol counterparts on a variety of parameters.
Adding to this price difference are India’s strict emissions standards, which diesel engines are more difficult to meet than petrol engines. The BS6 regulations passed in 2020 are so strict that many brands have abandoned diesel engines altogether, as the cost of upgrading these engines would further widen the already wide price gap between petrol and diesel vehicles.
With the implementation of phase 2 of BS6 from April 2023, many diesel cars/engines will be retired as upgrading them to meet the new norms will increase their price from Rs 20,000 to Rs 50,000, which will further reduce already weak diesel sales.
Given these facts, is it wise to buy a diesel car instead of a petrol car in 2023?
Petrol vs Diesel Car: Purchase Cost
| Car | Average price difference between equivalent petrol and diesel variants (ex-showroom) |
| Tata Altroz | Rs 1,31,250 |
| Tata Nexon | Rs 1,35,000 |
| Hyundai Creta | Rs 1,36,128 |
With the discontinuation of the Hyundai i20 diesel engine, the Tata Altroz is the only one in the segment to offer a diesel engine option. It is also the most affordable new diesel car you can buy in India today. Considering equivalent variants, the price difference between Tata Altroz petrol and diesel ranges between Rs 1.3 and 1.35 lakh, or an average of Rs 1,31,250.
Next, we look at the best-selling compact SUV (overall and diesel) in India, Tata Nexon, where the average price difference between petrol and diesel variants is Rs 1,35,000. Finally, we have the best-selling mid-size SUV in India (again, overall diesel), the SUV. Hyundai Creta, with an average price difference of Rs 1,36,128 between petrol and diesel variants.
Petrol cars and diesel cars: Fuel efficiency and costs Despite advances in technology, petrol cars still cannot match the fuel efficiency of cars run on diesel.
However, the difference between petrol and diesel variants is the same for automatic transmission models. Also, since BS6 stage 2 engines will be more efficient, you can expect the above numbers to change for the better.
Petrol vs Diesel Car: Maintenance Costs
| Tata Altroz | Tata Nexon | Hyundai Creta | |
| Petrol Mileage | 18.5 kmpl | 17.5 kmpl | 16.9 kmpl |
| Diesel Mileage | 23 kmpl | 21.1 kmpl | 21.4 kmpl |
| Difference | 5.5 kmpl | 3.6 kmpl | 4.5 kmpl |
However, fuel costs are only a part of the total operating costs, while maintenance costs are the rest. Diesel engines have higher maintenance costs than petrol engines for two reasons. First of all, greater mechanical stress in diesel engines leads to greater wear than in petrol engines.
Second, because diesel engine parts are built heavier to withstand this stress, they are more expensive to replace than petrol engine parts. While the exact cost of servicing petrol and diesel engines varies depending on the vehicle and your driving habits and conditions, here are estimates for each vehicle we reviewed.
This is an approximate estimate based on the official maintenance and replacement schedule of each vehicle. Your actual service costs may vary depending on the actual mileage you record, and the corresponding parts changes required, e.g. early replacement of engine oil, air filter, fuel filter or brake pads.
Related: CNG vs Petrol Car: Which One is Better?
Petrol vs. Diesel Car: Running Costs
Now that we have estimated fuel and maintenance costs, we can compare the actual cost of ownership between petrol and diesel cars for These three car models, on a scale of 5 – a five Stage. In 1 year, the diesel Altroz will save you Rs 14,630 in running costs compared to the petrol Altroz.
However, given the average price difference of Rs 1,31,250 between the two variants, you will need to own the Altroz diesel for nine years to make up for the extra you pay. Then, the Nexon diesel engine will save you Rs 13,890 in running costs compared to the Nexon petrol engine in 1 year.
But with the average price difference between the two variants being Rs 1,35,000, you would need to own the Nexon diesel for 10 years to recoup the premium you pay for the Nexon petrol. Finally, the diesel Creta will save you Rs 17,685 in running costs over the petrol Creta in 1 year.
Considering the average price difference of Rs 1,36,128 between the two variants, you would need to own the Creta diesel for eight years to eliminate this difference. For ease of understanding, these calculations are based on factory price only and therefore do not include your state’s local taxes and insurance premiums.
Once these figures are factored in, the difference in running costs reduces even further, as taxes and insurance premiums are higher on diesel cars than on petrol cars. In other words, this means you need to increase the ownership period mentioned above by 2-3 years to get an accurate idea of what you will need to own a diesel car versus a petrol-powered car to compensate for the first person’s additional insurance premiums.
Petrol vs. Diesel Car: Variable Cost of Ownership
Now that you understand how to calculate the total cost of ownership, it’s worth considering different use cases when comparing cars. These use cases are based on “recommended fuel” based on the amount of driving you do each year. Our calculations assume an average monthly driving of 1,000 km, which corresponds to an average of 12,000 km driven per year.
For the next comparison, we will only consider the Tata Nexon with an average monthly driving distance of 500 km and 2,000 km, which translates to 6,000 km and 24,000 km of annual driving respectively makes it very clear which fuel is the best choice for a particular type of operation.
Here’s a quick look at the three charts:
For short trips under 1,000km per month, petrol cars are still cheaper to run, even after 15 years.
- For a mix of short and long journeys, i.e. around 1,000km per month, 10 years is the average time it takes for a diesel car to become cheaper than petrol.
- There is a small difference after 10 years and a significant difference after 15 years between petrol and diesel, which chooses between the two more nuanced.
- For most long-distance trips of at least 2,000 km per month, a diesel car would be the preferred choice as its running costs are much lower.
- To get the best return, you should ideally drive your diesel car for 15 years.
Should I buy a diesel car?
Buying a diesel car makes sense if your annual mileage is over 15,000 km and you plan to own the car for at least 10 years. The additional premium you pay for a diesel car gives you two unique benefits i) higher fuel economy and ii) torque distribution for comfortable driving equally on highways and city streets.
But if you live in NCR, owning a diesel car older than 10 years is prohibited by law. But if you live elsewhere, the law still allows you to own a new diesel car for 15 years and renew the registration after that period every five years, making the car diesel new or used becomes a viable option.
The latter is a trend that the Indian auto market is witnessing as the average car ownership period in India is currently 5 years and is decreasing.
In such cases, the lower price of a petrol car will provide better overall savings than a diesel car. That said, with tighter emissions standards and an increasingly narrow spread between petrol and diesel prices, many diesel cars will be phased out as India moves towards the adoption of more cars.
Unless you log a lot of miles per year, can keep your car for more than a decade or like the strong torque of a diesel engine, a petrol car is the better choice, a wisdom that Indian car buyers have gained experience over the past decade.
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