Diesel or Gas - Are expert opinions misleading?. Review on Petrol Vs. Diesel car

Please note that when I say Gas, I mean Petrol and not LPG / CNG.

I have done a bit of research on the topic of Diesel or Petrol and I am kind of vexed and frustrated with the confusion on this topic. For a guy like me, who is on the cusp of things really with a distance of about 25 to 30 kms per day, this indeed is a decision worth a serious thought.

Open any expert websites on the topic and they all say one thing - 1500+kms a month and you are better off with a diesel. On the other hand though, the diesel engines have gone through a revolution and the price benefits on fuel that they show are always tempting.

Now, the experts opinion of a minimum run of 1500+ kilometers is guided by a single factor and that is to offset the addition 60, 000 to 100, 000 bucks we pay for a diesel equivalent. Are they justified in saying so, let us have a bit of a calculation into it from a different perspective - never mind, my maths is not exemplary and it is pretty much down to basics.

For an additional 80, 000 bucks(I am in the middle of things), let us say that the general depreciation per year is 20%, so, a diesel vehicle would depreciate by a further 16, 000 bucks per year as compared to a petrol.

Now, add an additional 2500 bucks per year to this as an extra maintenance cost since we are in a world which assumes that diesel demands more maintenance - 2500 bucks an year is good enough to give the car about 2 quality services - I hope the amount is justified.

So, an extra cost of 18, 500 is incurred as we run on diesel.

Now let us see what it translates to in terms of number of Kms to be clocked.

Avg cost per km on petrol = 50/12= 4.2 approx. Let us say 4.5 considering inflation over the next 3 to 5 years.

Avg cost per km on diesel = 38/15 =  2.55 approx. Let us say 2.8 for the same cause of inflation.

So, for every km, the diesel saves us about 1.7 bucks.

So, number of kms to be clocked at a minimum for a diesel to be economical - 18, 500 / 1.7= 10900(approx) kms an year or 900(approx)  kms a month.

With the quality of a diesel engine improved leaps and bounds, there are a lot of people who feel that the difference in maintenance costs is getting negligible these days and effectively it only means that,

the extra cost for diesel car would be 16000 bucks. Hence, number of Kms to be clocked - 16000 / 1.7= 9400(approx) kms per year= 785(approx) kms per month!

So, are the expert right when they say - 1500 kms a month and only then a diesel? Well, experts are right and they always are. The reason being the assumptions which are:

1. Diesel Engines are tuff to maintain - this is a thing of the past - even if they demand a bit more of maintenance - say an additional 2500 bucks or 2 additional services a year, they are still economical at 900 kms a month.

   
   




2. The additional cost incurred in a diesel - well, here a diesel engine is surely more expensive, but, in terms of depreciation, I believe it is pretty much the same percentage depreciation per year and hence we should consider depreciation per year alone. Just to get it straight, a diesel car would fetch probably about 65000 bucks more than a petrol engine after one year of usage(if the initial cost is additional by 80000)

   
   

Moreover, with a lot of taxi drivers preferring diesel versus petrol, it should be easier for anyone to dispose off a diesel as compared to a petrol!

So, why petrol? I seem to have created an extremely negative opinion about petrol engines, but, on any day, the quality of refinement that one would get out of a petrol is unchallenged by a diesel engine and that is what is the reason why petrol engines inspite of them not being cost effective, still make sense to go for - particularly in cases where usage is less than 8000 kms a year. Say, the extra cost associated with a petrol pays off in the form of refinement.

The next time you have a question on how many Kilometers to breakeven in terms of cost, read it as around 859 to 900 kms a month.