Choosing between a petrol and a diesel car has always been a tough decision for buyers. While petrol cars have traditionally been the go-to choice for city driving, diesel cars have dominated highway and commercial segments. However, with changing fuel prices, stricter emission norms, and advancements in engine technology, the debate has become more complex than ever.

In this detailed guide, we will compare petrol and diesel cars across various parameters, including initial cost, mileage, performance, maintenance, and resale value. This will help you make an informed decision based on your driving needs and budget.

1. Price Comparison: Initial Cost vs Running Cost

Initial Buying Cost

Diesel cars are generally more expensive than their petrol counterparts. The price difference can range between ₹1 lakh to ₹2.5 lakh ($1,200 to $3,000), depending on the car model and manufacturer.

For example, the Hyundai Creta petrol variant costs ₹11.00 lakh, while the diesel variant costs ₹13.90 lakh, making a difference of ₹2.90 lakh. Similarly, the Maruti Suzuki Brezza petrol variant is priced at ₹8.30 lakh, whereas the diesel variant is ₹10.00 lakh, with a difference of ₹1.70 lakh. The Tata Nexon petrol starts at ₹8.10 lakh, and the diesel version is ₹10.40 lakh, showing a difference of ₹2.30 lakh.

Running Cost (Mileage & Fuel Price Impact)

• Fuel Prices in 2025: Petrol costs ₹105 per litre, while diesel is priced at ₹92 per litre.
• Mileage Differences:
• Petrol Cars: 16-18 km/l in city driving and 18-22 km/l on highways.
• Diesel Cars: 20-22 km/l in city driving and 22-26 km/l on highways.

Cost Per Kilometer (Approximate)

A petrol car with an average mileage of 18 km/l costs approximately ₹5.83 per km, while a diesel car with an average mileage of 22 km/l costs about ₹4.18 per km. Over a 5-year ownership period, with an average of 15,000 km per year, a diesel car can save around ₹1.24 lakh ($1,500) in fuel costs.

2. Performance & Driving Experience

Torque & Power Output

• Diesel engines provide higher torque, making them ideal for long drives and highway cruising. For example, the Hyundai Creta Diesel produces 250 Nm of torque, compared to 144 Nm in the petrol variant.
• Petrol engines offer smoother performance and better refinement, making them suitable for city commuting and short trips.

Noise & Refinement

• Petrol engines are quieter and more refined.
• Diesel engines, though improved, still produce more vibration and noise.

3. Maintenance & Service Costs

Diesel cars generally have higher maintenance costs due to turbochargers, fuel injectors, and particulate filters, which require periodic servicing and cleaning.

• Service Cost (Per Year): Petrol cars cost between ₹5,000 – ₹7,000, while diesel cars cost ₹8,000 – ₹12,000.
• Engine Longevity: Petrol engines last around 10-12 years, whereas diesel engines last between 12-15 years.
• Common Repairs: Petrol cars require spark plug and coolant maintenance, while diesel cars often need turbocharger and injector servicing.

4. Emissions & Environmental Impact

BS6 Norms & Pollution

• Petrol cars emit fewer pollutants like NOx and PM (Particulate Matter).
• Diesel cars, even with DPF (Diesel Particulate Filters), still emit more nitrogen oxides.
• Many cities worldwide, including Delhi and Paris, have started restricting diesel vehicles.

Electric & Hybrid Alternatives

With the rise of EVs (Electric Vehicles) and Hybrids, the long-term viability of diesel cars is in question. Many brands like Maruti Suzuki, Honda, and Volvo are shifting focus toward petrol, hybrid, and electric cars.

5. Resale Value & Market Trends

Diesel cars traditionally held better resale value due to fuel efficiency. However, trends are changing as petrol and hybrid cars gain popularity. In 2025, petrol cars retain 65-70% of their value after 3 years, while diesel cars retain 60-65%. After 5 years, petrol cars have a resale value of 50-55%, whereas diesel cars stand at 45-50%. Beyond 7 years, petrol cars retain 35-40%, while diesel cars drop to 30-35%.

Many diesel cars lose resale value faster as governments phase out older diesel models due to emission concerns.

6. Conclusion: Which One Should You Buy?

Buy a Petrol Car If:

✔ You have a lower budget. ✔ Your daily driving is under 50 km. ✔ You prefer a smoother, quieter engine. ✔ You plan to keep the car for over 7 years.

Buy a Diesel Car If:

✔ You drive over 1,500 km per month. ✔ You frequently take long highway trips. ✔ You need a powerful engine with better fuel economy. ✔ You plan to sell the car within 5 years.

Final Verdict

In 2025, with stricter emission norms and fluctuating fuel prices, petrol cars make more sense for city driving and long-term ownership, while diesel cars are still a great choice for high-mileage drivers. However, with the rise of hybrids and electric cars, diesel vehicles may soon become a less attractive option.