I did my own calculation to find out the break even between petrol and diesel car price difference, for this I considered following:
1)Cost Difference between similar variant= On road price difference.
2)Interest accrued @10% over the difference for a period of 5years.
3)Maintenance charges Rs2000/- for every 10000km for petrol and 5000km for diesel.
4)Fuel cost Rs 67.33/- for petrol and Rs 44.1 for diesel.
5)(Assumption on) On road mileage~ 3kms/liter less than the mileage at std conditions.
Based on the above-mentioned points, the break-even happens at~70000kms, after this the diesel variant becomes profitable.