[Racer911]

Originally Posted by romeomidhun

He is talking about Rs 1/- difference between per-KM cost, not per-Litre difference.

Hmm.. maybe you're right. But the way he wrote difference in fuel cost of Re.1/- is what got a little confusing.

Thanks anyway.

[ACM]

Both The Excel based calculators are quite good.

One could use them to compare old and new cars both as also one old with one new - as long as one considers the difference in interest rate and down payment separately and adds to the initial cost calculation.

A new parameter that can be added based on the recent court ruling is that for Diesel vehicles the residual value after 10 yrs should be close to ZERO, while it would be ZERO for Petrol vehicles after 15 yrs. (Assuming that these recent rulings and trends (Dumb ones no doubt) become the national standard in years to come.).

Calculating for a preowned vehicle and a new one and also calculating considering the Interest on loans one comes up with some very radical figures.

While one should also consider which is a better engine (for FE and for Performance) and hence more joy to drive or more economical to be driven in. It is always good to have a basic calculator to compare the economics of two vehicles before buying them.

[Blow Horn Ok]

After the diesel Indica, we were all set for the petrol swift in 2010. But ford launched the figo at the same time and the price difference between the petrol swift and diesel figo wasn't much. We went with the figo for being diesel, better build and solid feel. Did we recover the additional cost in these 6 years by driving only 50000kms with respect to similar specced petrol figo? No. But what we got was better engine in comparison to petrol one in terms of efficiency and torque. So as GTO pointed out, it all boils down to the the car you chose and the range of engine it offers. But for entry level cars which are offered only in petrol, this theory won't work.

[auto_enthusiast]

Originally Posted by GKMahajan

Dear auto_enthusiast,

Are you a Gujju businessman by chance?
Just joking! No offense intended!

I like the simplicity of your logic.

I too have a similar logic: if the diesel costs 1,00,000 more than the petrol - and - if the fuel costs differ by Rs 1/km, then you have to drive 1,00,000 km to recover it. Divide this by the distance you travel per unit time - you get the time to recover your additional investment. NOW, you can decide - based on your priorities - is this worth it or not?

Regards,

Girish Mahajan

No offense taken sir, BTW I'm a Marwari businessman

Apart from your calculations, I've taken the additional resale value also into consideration and this helps in making a fair comparison.

Calculations aside, I would still go for a diesel because of the addictive torque, powerful engine which itself seals the deal in favor of diesel.

[GKMahajan]

Originally Posted by Racer911

How can that be?? I think I would safe in assuming that a petrol car would give about 17 Kmpl in the same scenario in which a diesel would give about 20 to 20.5 Kmpl.

Now if theres a difference of Re. 1/- in the fuel price and the diesel costs 1 Lakh more than the petrol, then say if petrol costs Rs. 61 and diesel costs Rs. 60/-, then cost of running per Km for petrol and diesel is Rs. 3.58/- and Rs. 3/- respectively. So in a diesel you're saving Rs. 3.58-Rs3/- i.e. Rs. 0.58 saved per Km. So with 100000 Kms of driving you save Rs. 0.58 x 100000 = 58000 Only. So to cover the extra cost of Rs. 100000 you'd have to drive 100000 divided by 0.58 i.e. about 172400 Kms.

Hope I didnt goof up anywhere.

Dear Racer911,

You got it perfectly. I had used rounded numbers to explain the concept. In fact, when I was doing this calculation on real life cars, I got a difference in the range of 0 Rs/km to as high as 2.5 Rs/km. Off hand I do not remember the car models involved! Sorry!

Girish Mahajan

Originally Posted by romeomidhun

He is talking about Rs 1/- difference between per-KM cost, not per-Litre difference.

Dear romeomidhun,

Thanks for the reply on my behalf. My response is above.

Girish Mahajan

Originally Posted by auto_enthusiast

No offense taken sir, BTW I'm a Marwari businessman

Apart from your calculations, I've taken the additional resale value also into consideration and this helps in making a fair comparison.

Calculations aside, I would still go for a diesel because of the addictive torque, powerful engine which itself seals the deal in favor of diesel.

Dear auto_enthusiast,

Thanks for the positive response!
You are right about the resale value and addictive torque. Of course, on the flip side - you have missed the noise, vibration and lower power (pickup)....

Girish Mahajan

[romeomidhun]

Assume:

Difference between Petrol and Diesel model: Rs 1 Lakh
Yearly interest for Rs 1Lakh: Rs 8,000/-
You can fetch 50K out of the 1L you spent for Diesel model while you are selling the car, and your break-even will happen when you fetch the remaining 50K.
Yearly running: 20,000KMs (monthly running: 1600KMs)
Yearly additional maintenance expense for Diesel: Rs 4,000/-
Yearly additional driving expense (just because it is Diesel, you may drive an additional 50KM monthly): Rs 2,000/-
Petrol price: Rs 64/-
Diesel price: Rs 60/-

Case 1: Consider this: You have a very fuel efficient driving circumstances:


Cost per KM for Petrol: Rs 3/- (64 / 21 = ~3)
Cost per KM for Diesel: Rs 2.3/- (60 / 26 = 2.3)
Yearly extra expense for Petrol: Rs 14,000/- (20000 * Rs 0.7/-)

Effective additional expense for Petrol per year: 14000 - 8000 (interest) - 4000 (maintenance) - 2000 (additional driving) = Rs 0/-

You cannot fetch the additional 50K at any time, and Petrol is the obvious choice here.


Case 2: You have a sufficiently fuel-efficient Petrol model, and you will use a hard foot when it is Diesel.

Cost per KM for Petrol: Rs 4/- (64 / 16 = 4)
Cost per KM for Diesel: Rs 3/- (60 / 20 = 3)
Yearly extra expense for Petrol: Rs 20,000/- (20000 * Rs 1/-)

Effective additional expense for Petrol per year: 20000 -8000 (interest) - 4000 (maintenance) - 2000 (additional driving) = Rs 6000/-

To fetch the remaining 50K, you need to drive the car for more than 8 years (8 * 6K = 48K), which is the breakeven period, and no need of a Diesel car here.


Case 2: Now, consider this: (the mileage of Petrol car is very less compared to Diesel):

Cost per KM for Petrol: Rs 5/- (65 / 13 = 5)
Cost per KM for Diesel: Rs 3/- (60 / 20 = 3)
Yearly extra expense for Petrol: Rs 40,000/- (20000 * Rs 2/-)

Effective additional expense for Petrol per year: 40000 - 8000 (interest) - 4000 (maintenance) - 2000 (additional driving) = Rs 26000/-

To fetch the remaining 50K, you need to drive the Diesel car just 2 years (2 * 26K = 52K), which is the breakeven period, and go for Diesel here!

[jetsetgo08]

Originally Posted by romeomidhun

Case 2: You have a sufficiently fuel-efficient Petrol model, and you will use a hard foot when it is Diesel.

To fetch the remaining 50K, you need to drive the car for more than 8 years (8 * 6K = 48K), which is the breakeven period, and no need of a Diesel car here.

Could you please edit case 3 to 'case 3' in your post.

Case 1 & 2 is where most of us would fall under. However, a difference of just Rs.4 between petrol and diesel is just limited to a few locations and highly optimistic even if the fuel prices surge in the near future.

I doubt there would be a difference of Rs.4000/year for maintenance. In which case the break even would reduce to 5 years from 8 years. Anything beyond would yield benefits of using a diesel. Assuming a monthly mileage of greater than 1500 km.

Case 3 is categorically applicable for all C2 sedans and SUV's,even with a monthly running of 1000 km's.

[romeomidhun]

Originally Posted by jetsetgo08

Could you please edit case 3 to 'case 3' in your post.

Thanks. Moderators, request you to kindly update this.

Originally Posted by jetsetgo08

...a difference of just Rs.4 between petrol and diesel is just limited to a few locations and highly optimistic even if the fuel prices surge in the near future.

Even if we consider a difference of RS 6/-, there won't be much of a difference than a maximum of 10-20 paise.

Originally Posted by jetsetgo08

I doubt there would be a difference of Rs.4000/year for maintenance.

Just consider the additional expense for the oil change twice a year. On major services like 40K, the difference is very much visible.

[shadows123]

Shouldn't we also consider the company you're buying the car from? All these calculations aren't worth much if you buy from the wrong company since that's not their forte.

For example Fiat , VW , Skoda --> Diesel (Never petrol since their diesel is very superior) , Very high cost of maintenance in case of the last 2 in the list.

Honda --> Petrol(Since their european diesel tech is not adopted here?)

Only Hyundai(Questionable diesel?), Maruti , Tata(Questionable Petrol?) , Toyota would these be applicable?

Not sure where Ford,Chevy would fall since i haven't driven it to comment.

[Chrome6Boy]

The TSI motor from VAG is one of the best petrol motors around. Even though the TDI is great, TSI cannot be ignored and is certainly their forte.

Originally Posted by shadows123

Shouldn't we also consider the company you're buying the car from? All these calculations aren't worth much if you buy from the wrong company since that's not their forte.

For example Fiat , VW , Skoda --> Diesel (Never petrol since their diesel is very superior) , Very high cost of maintenance in case of the last 2 in the list.

Honda --> Petrol(Since their european diesel tech is not adopted here?)

Only Hyundai(Questionable diesel?), Maruti , Tata(Questionable Petrol?) , Toyota would these be applicable?

Not sure where Ford,Chevy would fall since i haven't driven it to comment.

[Racer911]

I guess I'll have to request mods to maybe close this thread. The discussions have gone too wayward and the purpose of the thread is now accomplished

[Maverift]

Originally Posted by shadows123

Only Hyundai(Questionable diesel?)

Why in your opinion is Hyundai's diesel cars questionable? i20 Verna (and by extension Creta) have excellent diesel engines compared to their petrol counterparts.

[nikhilarni]

Originally Posted by Racer911

Hey Guys,

For all the people still confused between diesel vs petrol feasibility, I've created a simple excel sheet with basic variables that will give you a pretty accurate time period to cover the extra cost of a diesel, if at all you're planning for a diesel for cost saving purpose in the first place..

Check it out and do let me know if you think there's some flawed calculations.

its in the attachment.

Hi Racer911,

This is good stuff.

I had done a similar exercise in 2011 when I bought my diesel i20. My wife being a CA helped me with the amortization. I will share that excel as well.

The addition that can be made is, in case the loan is through an OD account. Mine was an OD loan from SBI.

But this is a great start.

[jaaz]

Two points to be considered:

1. Maintenance cost of both the Engines. In the last decade, maintenance of Diesel Engines has come down drastically.

Someone can enlighten us about the difference in cost of say, Swift Diesel and Petrol. Or any other manufacturer or model, where both the Engines are available.

2. In City Traffic, Engines run more in Idle time. Which fuel has the edge? Not considering the people, who stop their Engines. Can someone quantify this?

For ex.: In B'lore, it'll take about approx. 1 hour to travel 10 kms in peak hours (Central B'lore).

[teemus]

Originally Posted by Racer911

Hey Guys,

For all the people still confused between diesel vs petrol feasibility, I've created a simple excel sheet with basic variables that will give you a pretty accurate time period to cover the extra cost of a diesel, if at all you're planning for a diesel for cost saving purpose in the first place..

It's a good pointer for someone who is confused between Petrol and Diesel based on the day-to-day running. Gives a good idea of break-even point, making the decision simpler.

But, this does not (and is not even intended to obviously!) take into consideration the FTD for the turbo diesels and the happiness quotient it brings each time you are driving till that break-even point is reached.

Now in my case, I have Figo 1.5D and it just blows away it's petrol counterpart in terms of performance. This while being cheaper on the pocket even when you rip her around on the highways. My running of average 50km per day can be said to be on the verge of petrol vs diesel switch-over; but one drive with the diesel car put it decisively in diesels favour.

Also, since day-to-day you make less trips to the fuel station, make you feel good and in turn you drive the car more.

If I were to have petrol, I wouldn't average 50km per day for sure.