As per current situation diseal model is on higher side. Almost 1.5 to 2 Lac difference. If you go with diseal then still you need to recover your money after 7-8 year. Also diseal car value validity is 10 years. So as per my point of view you should go with Petrol as per your running.
Kaha chalte ho bhai aisa jo diesel main 26 ki bol rahe ho humhe bhi bata do humhri toh nahi aati 13 14 se jada or brand new car hai 1000 km chala di hai