Very good thread with excellant idea
Stage 1:
If person needs better NVH levels, easy and fun to drive, long lasting smooth engine, less visit to service shop, not bothered about resale value, not bothered about fuel bills then I suggest Petrol Innova which is simply best car I have seen so far.
If person clocks more than 20,000km per year and looking for lower fuel bills and not keeping the vehicle more than 4 years or 2 lacs kilometers (whichever comes first) then Diesel Innova makes sense.
Innova V spec is best one to choose because its loaded with features. I like and suggest 8 seator for family use and 7 seator Innova is suitable for taxy operators and corporates.
Stage 2:
Buying cost: After bargaining the discount on any variant Petrol one is 1+ lac. rs. cheaper than corresponding Diesel counterpart.
Stage 3:
Fuel cost: Every kilometer we can save 3 rs. from Diesel Innova.
Petrol (1+ lac savings while buying) and Diesel Innova cost will come to equal value once Petrol Innova clocks 37,000km. Here 33,000km (3 rs savings per kilometer from Diesel Innova) as Fuel Bill differance and 4000km as service/maintainance cost.
Diesel Innova needs service once in 6 months or 5000km where Petrol needs once in a year or 10,000km!
When Innova has covered 37,000km Petrol needs 2 free + 2 paid service where Diesel needs 2 free + 6 paid service so its nothing but 4 extra service for Diesel variant and hence 4X3000=12000/- rs. extra.
Stage 4:
TCO: 1 lac kilometer means 20 service for Deisel Innova and 10 service for Petrol Innova. Based on what I understood from Toyota person it would be at least 60,000/- for Diesel and 30,000/- for Petrol, it might be more than this for variants based how abused/circumstances we came across the vehicle/place. So per kilometer its 30 paisa for Petrol and 60 paisa for Diesel.
So in long run over all difference between cost of ownership of variants:
The below
Fuel Bill + maintainance value might be slightly change based on individual but will be in this ratio.
Diesel: Fuel Bill + maintainance = 2.85 + 0.60 = 3.45 rs (Assumming 37 rs is diesel cost and avg FE 13)
Petrol: Fuel bill + maintainance = 5.91 + 0.30 = 6.21 rs (Assumming 52 rs is Petrol cost and avg FE 8.8)
PS: Average FE calculation: Petrol would give 7kmpl in city and 10.6kmpl in highway hence average FE is 8.8kmpl.
Diesel would give FE between 11 and 15 hence 13 is average FE.
Resale value: While buying Petrol innova we can see 2.2 lacs. difference between the price compared to Diesel ones.
Example: V spec. 2005 Diesel Innova trades at 8.2 lacs. where as V spec. 2005 Petrol innova at 6 lacs.
Regards,
Ravi.