[Delta Wing]

This gives a calculator for the running cost of a vehicle and a means to compare two sets of two vehicles.

Mods: I started a new thread a while back which seems to have vanished in blue smoke. I haven't found what I'm posting here on TBHP.

Background:

The steep hike of petrol prices a few days back got me thinking about whether a petrol car is really worth it. Read in TOI yesterday that with the difference in prices of Petrol and Diesel, the initial cost vs operating benefits break-even period for a Diesel car has come down drastically right down to 18 months. Didn't sound convincing. Other people I asked gave varying figures. Finally, opened an Excel sheet and worked it out with some assumptions. The results, even though anticipated, amazed me to say the least. Suggestions welcome.

The running cost calculator:

It's very simple to use. If you want to change the basic figures such as fuel prices, FE, mileage, just change the figures in red to anything you want and the resultant values are updated. I've built down to up from Petrol/Diesel prices and their increments spread over 15 years (or interval, to be more accurate), the mileage values as per personal requirement, the FE expected from the cars (two samples used for C+ and C Segments, it could be any two segments) and the result table is generated by the software.

The result table which I named Running Costs calculates:-

1. The running cost per km from the FE and fuel price that fed in.
2. The yearly cost for your mileage with the above values of running cost/km.
3. The yearly saving you get from running an oil burner for the above values.
4. The progressive saving you get as the years go by.

The weak areas in the assumptions I made:-

1. The trend of pertol/diesel prices is extrapolated over too many years and I don't have much knowledge of the expected trends. If anyone can shed light on these or update the sheets, it will be great.
2. The FE I've assumed will vary greatly from each specific car to another car (car condition, driving style etc) so you have to feed the exact FE you see on your vehicle or accurate figures reported by others. This is not a flaw as such since the figures are readily available/ can be safely amended as required.
3. I appear to have given more benefit of doubt to Petrol in terms of FE and done injustice to Diesel prices by having the same rate of inflation. This too can be corrected by some tweaking with the FE figures and a little more tweaking with the yearwise Diesel price growth coefficients.

As of now, I've put in five sheets in the Excel file and I'm attaching screenshots of these below too. These show:-

1. Calculations for a yearly running of 8,000 km/yr.
2. Calculations for a yearly running of 12,000 km/yr.
3. Calculations for a yearly running of 16,000 km/yr.
4. Calculations for a hypothetical scenario if Diesel subsidies are gradually reduced by overinflating Diesel prices and regulating Petrol prices over 8 to 9 years. Only for mileage of 8,000 km/yr.
5. Calculations for a hypothetical scenario if Diesel prices are gradually equalised with Petrol prices by deinflating Petrol prices over 8 to 9 years. Only for mileage of 8,000 km/yr.

Expect a lot of bashing for the last two. They are much the same really.

Finally, here's the stuff.

The Excel file:

Running Cost Calculator.xlsx

The screenshots (click images to see readable figures):

For 8 K km/yr:



For 12 K km/yr:



For 16 K km/yr:



For Diesel gradually bought at par with petrol:



For petrol deinflated and equated till Diesel catches up:



The results speak for themselves and how. The situation of prices just screams 'Diesel' for ANY medium-long term car ownerships, even if Diesel prices were to equal those of Petrol (see the figures after ten years in the last two sheets, sheer force of more FE gives oil burners an edge there too). Our redline loving friends on the forum are not going to be happy with these figures. But then they didn't care about economical ways in the first place, did they?

The excel document need not necessarily mean a petrol vs diesel comparison. If you disregard the petrol/diesel words and put in the appropriate figures, any two sets of cars can be compared.

This tool could become a useful database for all members looking to find economy of operation of any model of any car. Any member generating a sheet with their own data for their own car could please upload it all to see.

Hope you guys find it useful. It sure changed me totally from wanting a petrol car to a diesel car. Cheers.

-Hrish

[GTO]

Wonderful attachment, thank you for sharing.

The Rs.24 difference between a liter of petrol & diesel is staggering. What's more, diesel cars are inherently more fuel efficient than their petrol counterparts too. Example : A swift VDI easily gives 3 - 4 more kpl than a Swift VXi.

As you rightly said, the breakeven period for a diesel car has fallen. I can think of some models where you can recover the difference in 30,000 - 40,000 kms itself. Plus, common-rail diesels are today as fast (if not faster) and offer much better driveability too.

Clearly, the proportion of new diesel cars is going to shoot up. And, I hear, the oil companies aren't done yet. They are going to take the cost of petrol to 75 bucks!

[New.Novice]

You know, I feel cheated. Though no one else to blame then myself.

I bought a Petrol last year after seriously considering a Diesel. But all I could hear was that the "fuel" is going to get regularised. No where did I hear that it was only petrol. Keeping that in mind, I thought it doesnt make sense to buy a diesel at a premium.

Now, my own calcualtions, with this conclusive proof in the shape of your excel sheet proves that I have actually made a mistake. The break-even point could have come somewhere slightly less then 3 years time and from there on it was all saving my hard earned money.. earning which is whatever I have left with having paid each ounce of due taxes like all other salaried people in India

[VW2010]

Clearly, the proportion of new diesel cars is going to shoot up. And, I hear, the oil companies aren't done yet. They are going to take the cost of petrol to 75 bucks!

Thats a good sign to sell some old cars as well. I am in the market to sell my 3 year old Swift VDI to get something smaller for my wife. The way things are going @75rupees per litre i have a great chance to buy a new car spending nothing

[phamilyman]

There are two things :
a. The numbers (essentially two synthetic scenarios) say one thing - perkm petrol costs 2.5rs more. Hence, with 16k+/year in a C segment it makes more sense to buy a diesel. given a diesel engine costs 1.1L more. Which we anyways knew
b. If one wants to just buy cars based on projected savings and excel sheets instead of real world drivability & driving pleasure - may I suggest you buy your next car as a tata Diesel? heck - why buy it at all, I am sure we can cook up calculations that show that under 12k/year - its cheaper to rent than buy. Why even buy at all?

Lastly, like a certain gent by the name of anupmathur once said - buying cars is an emotional process. You cannot put the price on fun. Why buy fancy phones? Buy an el cheapo 1000 rs simple phone to call, no? Saves 15-20k/year clearly.

Bah.

[asr245]

Originally Posted by Delta Wing

Our redline loving friends on the forum are not going to be happy with these figures. But then they didn't care about economical ways in the first place, did they?

Well, not really. I still would prefer a petrol over diesel for fun. Mainly coz of the sweet music a petrol engine makes while redlining it. If this trend continues maybe petrol cars would be treated like horses - diesel for running around and petrol for that extra fun factor.

[New.Novice]

Originally Posted by phamilyman

Lastly, like a certain gent by the name of anupmathur once said - buying cars is an emotional process. You cannot put the price on fun. Why buy fancy phones? Buy an el cheapo 1000 rs simple phone to call, no? Saves 15-20k/year clearly.

Bah.

Thats a view point, for sure it is. I may not subscribe to it while you do.Which is only fair. In an economy and society like ours, car is still more of a luxury factor (increasingly on its way to neccessity) then someones desire to live his/her fun quotient.

Can we completely discard the fact that if one wants the "fun" within his means, thats not too much to ask for. Yes you buy a certain car with emotions but thats not all. If that was that, what stops a Cruze buyer from buying a BMW and a BMW buyer from buying a Porsche Cayman. Simple, its his means which moderates what is the definition of fun.

Same logic works the other way round when you gave that analogy of 1000 phone.And that is why my friend, if I can afford a certain Fiesta, I wont buy a Alto 1000.

In the process if one realise that one would have been better off buying a different varint (with little or no compromises on the fun quotient) but having paid a higher upfront price, I don't think the poor chap is not eligible to complain.

[Fordmanchau]

That's a real commendable attempt by deltawing to compare the running costs of petrol and diesel vehicles.
But, he has only considered fuel cost as a major component for arriving at his results and that's not a fair comparison IMO.
We all know there are many other factors that affect the ownership cost of petrol and diesel. Let's not even talk about the maintenance cost but atleast take into consideration the additional interest cost on the difference of price between diesel and petrol cars, may be at the rate of 13-14%.
Also, it would not be prudent to assume that petrol cost will increase 10%/5% every year.
As of now it might seem a practical assumption, but going forward as we truly progress to market economy, we might find that taxes are rationalised and both diesel and petrol are almost priced similarly.
Please keep in mind that processing cost of both the fuel is same and if the govt actually cuts taxes and deregulates the price of diesel and other fuel. We might just find that diesel is costlier than petrol as is the situation in other matured markets of the world due to market forced conditions.
Although a very good attempt to get a rough idea of the running costs but it is still far away from the ground situation and disconnected to the market conditions, I would say.

[mayankk]

Appreciate the effort. a lot of thought, and brains went in to it.
Anyone stuck trying to figure out which one to go for, its quite helpful.

However, for someone like me who's already a committed petrol/mental patient,this is too clinical.
Sensibility screams "diesel", but the hand doesnt want to reach for the chequebook still
but daayyuumm!!!
thats is some pot of gold there guys!

EDIT:

Originally Posted by New.Novice

Thats a view point, for sure it is. I may not subscribe to it while you do.Which is only fair. In an economy and society like ours, car is still more of a luxury factor (increasingly on its way to neccessity) then someones desire to live his/her fun quotient.

Can we completely discard the fact that if one wants the "fun" within his means, thats not too much to ask for. Yes you buy a certain car with emotions but thats not all. If that was that, what stops a Cruze buyer from buying a BMW and a BMW buyer from buying a Porsche Cayman. Simple, its his means which moderates what is the definition of fun.

Same logic works the other way round when you gave that analogy of 1000 phone.And that is why my friend, if I can afford a certain Fiesta, I wont buy a Alto 1000.

In the process if one realise that one would have been better off buying a different varint (with little or no compromises on the fun quotient) but having paid a higher upfront price, I don't think the poor chap is not eligible to complain.

I didnt get this.
are you agreeing with phamilyman, or disagreeing?
Fulfilling fun criteria qualifies as a luxury in my books.

[mayankjha1806]

Awesome work.

Question, most D's are about 1.5L more expensive than their petrol counterparts. Once i do the math my break even comes close to year 6. Is it than advisable to still go for Diesel?

[Newpunter]

Thanks for the great effort in making this. Seems like for my limited running ( I have managed a paltry 4K kms in nearly a year of owning my car ), Petrol still makes sense, without even considering the extra EMIs and interest on a Diesel car. But for others, it doesn't make any economic sense in getting a Petrol. I think if things continue this way, there is going to be an explosion in the number of private diesel vehicles and the government will have to start thinking about alternatives to subsidizing diesel.

[Figopian]

It's really a good spreadsheet for the buyers to compare. I had done my math before selling out my Xeta and went for figo diesel.

One thing though, getting the Petrol and diesel prices at par in the next five years seems too optimistic. I had thought this would happen in the next 5 years when I first bought my Xeta in 2006. The price difference then, between petrol and diesel has increased since then!!! So no wonder if this price difference still remains in the next 5 - 15 years.

[amulu10]

I had second thoughts about going for a diesel car with 6000km/yr running when i bought mine 2 years ago . Back then the difference was 15-16 so it wasn't clear cut decision. But with the recent price hike and the proposed hike to 75rs/l it does make sense to buy a diesel right now.
And for cars like the Fiat punto and most hatchback with 1.2l petrols , the diesel cars are up there if not faster than petrol car with great driveablity in city as a advantage. Diesel engine is no more a choice just for the economic reason , well at-least in the B segment it isn't .
But one fact we are forgetting is that , there is a possibilty that diesel prices will be deregulated sooner or latter with the losses mounting for the Oil cos.

[neel385]

Great tool. A lot of hard work seems to have been put in , so kudos!

That the data brings out the obvious is an understatement. Moreover, keeping costs aside, the fact that diesel burners give better mileage has another significant advantage. Its good for the planet. With the expendable income all over the world, specially the third world rising significantly, the number of vehicles on the roads are only going to increase thereby putting greater strain on the environment. Hence this itself is good reason to go diesel.
As far as the enthusiasts go, the refinement levels of diesels have increased significantly in the recent past. The fact that both the Le Mans and the Dakkar Rally have been won by diesels is testimony to the fact. It might take some time for such engines to come to our shores but then what we have is not too bad either.

[vishnurp99]

Even if the diesel prices are deregulated the diesel prices will only rise by 9 rs for the current international prices. Petrol will continue to be around 20 Rs more because of differential taxation. Petrol prices are also not fully deregulated right now. Oil companies continue to make around 5 rs loss per litre of petrol even after the humongous hike.