Diesel Vs Petrol Car Decision Making Calculator


We had written about this Diesel Vs Petrol Car decision making calculator back in 2012, when the petrol prices were going through the roof and diesel prices were relatively quite low. Now the scenario has changed quite a lot. Diesel prices have been increasing every month for past 6-7 months and it is interesting to see if the Diesel vehicles really maintain their edge.

The decision making calculator (link at the end of the post) gives you an excellent idea of which vehicle should you buy. Should it be a Diesel vehicle or should it be a petrol vehicle.

In our view, if you do not drive much, petrol car is a no brainer. However, if you do travel a lot, that too over long distances, you should definitely give this calculator a try. In certain cases, even if you drive quite a lot, owning a petrol vehicle can actually be quite beneficial.


Thanks to Petrol prices going through the roof, Diesel cars are now in great demand.

Many car buyers blindly make a decision to buy a Diesel car, however, the question is – Are Diesel cars really that beneficial to everyone?

To simplify the process of making decision of buying Petrol Vs Diesel car, a software engineer from India, Aravinda VK has developed a simple calculator.  This calculator can be used to analyze and decide which car is economical based on car buyers’ planned usage.

diesel vs petrol car

The car buyer has to just input his loan details, his usage details, expected fuel efficiency of the cars. The calculator will then immediately tell what the cost of running a Diesel car Vs a Petrol car will be for each year. From some of the calculations I made, here are some generic conclusions that could be arrived.

1) If your car runs less than 20 Kms a day on average (about 600 kms a month), running a Petrol car will be cheaper for  first 5 years atleast. I guess majority of home users will be in that bracket. So for them Petrol car is definitely the choice.

2) If you are on road frequently, Diesel is definitely the way to go because by 3rd year the cost of running a Diesel car becomes cheaper.

The calculator created by Aravind does not include Maintenance cost and generally, it is assumed that Diesel cars have about 25% to 50% higher maintenance cost as compared to Petrol cars.

Give Diesel Vs Petrol car comparison tool a try – I am sure it will help car buyers who want to make that decision.

  1. Ben says

    I am in a dilemma weather i should go for Petrol Ertiga or the SHVS Ertiga..Any suggestions?

    My usage is approx 5700 Kms per year.

    1. Arun Prabhudesai says

      If your usage is less than 6000 kms a year, you should definitely go for Petrol.

  2. Sandeep says

    2015 petrol car is best, only 62 prlit

  3. Anil says

    As per current fuel price difference, I think it won’t be worth going for a diesel model unless once drive on an average more than 1600 Kilometers/month. This calculation is based on a 5 year ownership period of a car including insurance and AMC costs.

  4. jalaja says

    Resale value not considered.. has there been an update of the tool lately. thanks.

  5. Kumar says

    Useful tool.

    However, the developer does not appear to have taken into account the opportunity cost of owning a Diesel car, which is at least Rs.100K more expensive than its petrol sibling. If one chose to go with a petrol car, and invested the price difference in an instrument yielding a conservative 10%, and drove no more than 1000 Km per month (which is about as much as one can clock in city usage alone with the occasional long drive), it would take atleast 16 years for the cost of ownership of the petrol variant to catch up with the diesel variant.

    1. Sameer Kulkarni says

      With opportunity cost under consideration, petrol cars would wash out all the advantages of diesel cars. Good point sir.

  6. abhi says

    Diesel engines are heavier by 40-50 Kgs hence more load on tyres and suspensions resulting in lesser life. Due to higher compression ratio battery life is less in diesel cars. Due to more vibrations component life is less. Also parts of diesel engine (Turbocharger etc.) are very expensive.
    check link

  7. jagjit says

    Although , the diesel is deregulated still then the price differentiation should be there as the diesel fuel is cheaper than the petrol one. Moreover , there is a mileage factor which is up in diesel car for 4-5 km per litre.As per experts calculations the diesel car will be economical for Rs.1.50/1.60 per km than the petrol one even in deregulation regime.The maintenence costs are almost same in both fuels.So if the car runs for 10000 km per year it will cover the 15000/- out of 100000/- paid upfront and so on

  8. GI says

    1) Diesel cars cost more upfront (a win for car makers who extract huge premiums from you!!)
    2) Diesel just got DEREGULATED!! What does that mean? Diesel costs more than petrol in all the deregulated markets!! Hence, it is possible that we in India might see diesel costs going through the roof in near future
    3) Insurance costs based on initial car value will be higher for diesel cars
    4) Recurring maintenance costs of Diesel cars is generally higher than that of Petrol cars (again a win for car makers!!)
    5) Diesel is more polluting than Petrol (let’s think a little bit about environment too, not just our wallets)

    Unless you are a taxi owner / driver, or you drive long distances everyday, there is no case for diesel cars given the deregulation scenario. Deregulation of diesel was much needed considering that govt was losing out 95,000 crores / year on this non-essential fuel.

    Consider all your requirements carefully. Don’t go by the marketing hype or near term appeal of lower cost of diesel alone.

  9. Bhagwan prasad says

    Diesel cars are costlier than petrol and better .comfortable itz better to go with diesel

  10. Amar Jadhav says


  11. Derivation From says

    Hi, the calculator is really great and will give a precise decision. But my cousin who is very adept in Cars has been using petrol car for more than 7 years says, when u have a car u will always be curious to drive long distances…you will not have control. And on top of it, Diesel prices will not go up that much when compared to Petrol….please suggest which car to buy. I am planning to hold the car for a period of 7-10 years. Also I was told that spending 4000 – 5000 Rs/- every month for petrol will be very burdensome while you can spend 1-1.5 Laks at a time on diesel and won’t feel that much burdensome monthly.
    Please advice.
    Look forward to all great people’s help.

  12. Jose Leshil Leshil says

    this calculation is working to make a dis…………

  13. SivaPrakasam Nagarajan says

    What happens if only the petrol price raise to tear open the roof, and diesel maintains? When I brought my petrol car, the petrol price was 52 rupees, but now it is more than 72, may be tomorrow or day after expecting a 6 rupee hike. Now what happens? Diesel only hiked about 6 or 7 rupees from then where as petrol hiked to 25 rupees. The monthly usage has to be reduced by the petrol car owners every month to keep the decision fair?

    1. alert says

      petrol is better, govt may remove subsidy on diesel for normal commuters

      read below link


  14. Prabuddha says

    Hi, are you sure most of the diesel cars will give 18 km/lt?

  15. ARVIND DUA says

    Diesel cars are more expensive to maintain always. Diesel engines are heavier by 40-50 Kgs hence more load on tyres and suspensions resulting in lesser life. Due to higher compression ratio battery life is less in diesel cars. Due to more vibrations component life is less. Also parts of diesel engine (Turbocharger etc.) are very expensive. Oil changing frequency is earlier in diesel engine.

  16. sandeep says

    i was informed my maruti sales person that for example if am purchasing following things always for service :-

    engine oil
    oil filter
    air filter

    these are three basic things for normal service agreed ??

    so for diesel car the price for those is 3 times more than petrol
    and same goes for other internal parts

  17. Facility Management Services says

    Really, good tool for those planning to buy a car. Some of the facts are missing from the calculator like maintenance cost, insurance cost, hike in price etc. so in my opinion perfect calculation can not be done.

  18. Akshay Bansal says


  19. Siddharth Karia says

    In my experience, diesel cars are about the same as petrol cars with reference to maintenance costs. In fact, in some cases even cheaper than petrol cars. What people don't realise is that regular maintainence is a requirement for any car. If you keep up with the service schedule and drive well, I don't see how a petrol car will be cheaper to maintain than a diesel. I'm using a diesel now, and comparing a petrol car of the same type costs the same to maintain. No more, no less.

    1. Arun Prabhudesai says

      Siddharth Karia I have never used Diesel car, so I am not really 100% confident about the maintenance costs… However, it is a general perception that Diesel Cards have higher costs in maintaining them… I may be wrong…

    2. Ramakrishna Girish says

      I do agree with you my friend since i had a plan of buying petrol car prior to buying the Ritz VDi @ siddharth karia and it is totally dependent upon u how u maintain the car and use it since the single hand drive for me really helps… 5 months and almost covered 6,000 kilometers….. still stands tall and rock solid and servicing and maintenance are as same as a Petrol car so why the hell go for a petrol car when u can enjoy the benfeits in a diesel car

    3. paripurna nand rai says

      Are you sure..?

  20. Sujith says

    It’s a good tool. But two things missed.
    (1) Recurring additional insurance cost.
    (2) Additional maintenance charges of Diesel cars.

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