[devarshi84]

Five forms of fuel. Which fuel is best for the car(Not a commuter)? I know that LPG and CNG cars are not available as standalone but they are still fuels of high choice in the market today. So considering all these five forms as standalone fuels for cars, which makes the most sense?If we can have a table like the one GTO has made for a LPG vs. CNG comparo would be great.

1. Which fuel gives more power from a similar engine?

2. Price and FE perspective.

3. Ecofriendly and Healthy.

4. More engine friendly (less maintainence and deposits?)

5. Just the way we see Diesels as less powerful but torquey and more FE compared to Petrols, how do LPG and CNG compare?

5. Diesels cost more than competitive petrol cars (fiesta, Swift etc) WHich also stands true for CNG and LPG (mostly because they are dual modes. ) which makes the most sense considering we dont use petrol to run cng/lpg cars?

6. Engine noise? I know diesel has more and electric has none.

I have seen a table by GTO on LPG vs. CNG but many would like to see a table between all the 5 fuel available. I know Maini Reva is the only car in the market but with The Volt rolling in N.A India will surely see the cars come in running on electricity.

[aaggoswami]

It depends a lot on usage. For me, if the car is a non commuter, I will go for Petrol.
But if all of your questions are answered, then it would be diesel. Newer diesels are cleaner than before, have good FE and huge amount of torque that helps a lot while driving.

CNG and LPG have their own set of limitations. CNG does not have that slight amount of lubricating property and hence the life of engine reduces. Moreover they have to stored under pressure, specially CNG. A cylinder for small car weighs in around 90 kg. This itself is negative. And storing high amount of any of these gases will take a lot of space. LPG and CNG are good for commuting within a city. They are ideal for that, less power but efficient.

Electric cars are yet to come up as highway cars.

Till then, Heart = petrol ( the way it revvs to 6K rpm + is nice ) and head = diesel.

[GTO]

Nice thread, Devarshi.

Originally Posted by devarshi84

Which fuel is best for the car(Not a commuter)?

Strange that, as much as the human race has evolved over the past century, the principles of the internal combustion engine stay the same. There has got to be a ground-breaking disruptive technology in our near future.

Which fuel gives more power from a similar engine?

In order of ranking:

Petrol
Diesel
LPG
CNG

However, bring TORQUE into the picture and it's diesel on top. We can't bring electric engines into this table due to their entirely different nature, though they do produce max torque at zero rpm!

2. Price and FE perspective.

Electric (dependent on a variety of factor though)
CNG
Diesel
LPG
Petrol

3. Ecofriendly and Healthy.

The jury's out on how eco-friendly electric cars really are (pollution as a result of generating the electricity). However, in terms of pollution from the car, electric rules the roost with zero emissions any day.

4. More engine friendly (less maintainence and deposits?)

I'd say a petrol is the simplest to maintain from the combustion engine type. Longest oil change intervals, modern petrols don't require tune-ups anymore while most Japs have a 200000 - 400000 km life.

The electric engine, on the other hand, is nearly zero maintenance. Minimal moving parts. The battery is probably the most substantial maintenance item (every 3 - 4 years on a Reva).

5. Just the way we see Diesels as less powerful but torquey and more FE compared to Petrols, how do LPG and CNG compare?

LPG is more powerful, CNG is more economical to run.

Engine noise? I know diesel has more and electric has none.

Answered it yourself.

[SS-Traveller]

Originally Posted by devarshi84

...many would like to see a table between all the 5 fuel available.

A sixth consideration may be the hybrids - petrol-electric (e.g. Honda Civic), or diesel-electric (e.g. Mahindra Scorpio hybrid, to be launched in the near future.)

[Parm]

its petrol for me anytime in india.

regular service and peace of mind!

diesel is for taxis, tractors, buses and trucks! so is CNG and LPG.

Electric vehicle is like having an AC at home and not enough volts to run it, have to buy an inverter or generator to run it!

[kannan666]

As a city runabout, I would prefer petrol for better pickup while for the highway, I would prefer a diesel for the additional torque. No experience with CNG, experience with LPG not good while an electric vehicle is still in it's infancy in India and we have no choice apart from the Reva which, for me, is too costly to own !

[GTO]

Originally Posted by Parm

diesel is for taxis, tractors, buses and trucks! so is CNG and LPG.

Parm, please test-drive the new gen diesels and you'll change your opinion. Common-rails are quicker (many of them) than their petrol counterparts, have far superior driveability, are more robust, way more fuel efficient and get you addicted to the torque. In fact, with most new launches, the diesel is generally more impressive than the petrol.

[StarVegabond]

Hi Nice thread, I agree with devarshi's analysis and GTO's comments.

we can add two more (likely) future fuels

1. Fuel Cells
2. Water

[carboy]

Originally Posted by GTO

The jury's out on how eco-friendly electric cars
really are (pollution as a result of generating the electricity).

A lot of electricity in India is generated from renewable energy sources
(hydropower etc) - so in those cases, this is a non-issue.

Even assuming the electricy comes originally by burning fossil fuels, I think pollution & efficiency can be better controlled in a power plant than in an automobile running on the road.

[raj_5004]

its the diesel for me. far more useful torque at a lower power band coupled with better FE & lower price of the diesel. the petrol is fine but the diesel clicks on all the right boxes, FOR ME!
CNG & LPG is a big no-no for me!

[sanagg1]

Originally Posted by GTO

In order of ranking:

Petrol
Diesel
LPG
CNG

.

Purely from scientific ponit of view the power in combustion engines comes from calorific value(CV) keeping combustion efficiency etc. constant the power as per various fuels ought to be proportional to CV which translate to following order

Diesel (Highest CV)
Petrol
LPG
CNG (Lowest CV)

thanks

[devarshi84]

I have put up a general table. Mods please edit it with correct facts and put it in my first post so that everyone can find it useful.

Petrol Diesel CNG LPG Electric
Pollution 3 5 2 4 1
BHP 1 3 2 4 5
Torque 5 2 4 3 1
Fuel efficiency (similar engines) 5 2 4 3 1
Cost of similarly equipped cars 1 4 2 3 5
Engine NVH 2 5 4 3 1




1. I know Electric wins here but I dont know where CNG and LPG stand against each other compared to petrol and Diesel.
2. I know that LPG is more powerful than CNG but where does it stand comapred to Diesel? What about electric cars which have power measured in KW?
3. I know Electric rules followed by diesels. Where do CNG and LPG stand compared to petrol?
4. Electric are the most efficient followed by LPG followed by CNG followed Diesel followed by Petrol.
5. Price of Electric are totally illogical negating almost all its benifits. Followed Diesel followed by LPG followed by CNG followed by petrol.
6. Electric makes no noise. But I dont know how CNG/LPG work compared to Petrol. Diesel makes most noise even in CRDI form.

[deepclutch]

CNG is what I feel the most economical one.it is not at all favoured in south India.Also ,some says an Engine Overhaul is Inevitable with CNG Cars(due to failure of fuel pump which gets dry due to lack of petrol~?).
remember ,most of the cars and other vehicles in Pakistan is running on CNG AFAIK.

[raj_5004]

Originally Posted by devarshi84

I have put up a general table. Mods please edit it with correct facts and put it in my first post so that everyone can find it useful.

Petrol Diesel CNG LPG Electric
Pollution 3 5 2 4 1
BHP 1 3 2 4 5
Torque 5 2 4 3 1
Fuel efficiency (similar engines) 5 2 4 3 1
Cost of similarly equipped cars 1 4 2 3 5
Engine NVH 2 5 4 3 1

assuming 1 = good & 5 = bad...
for BHP, you have written petrol=1 & diesel=3. i feel petrol engines have more power then diesels.
on the other hand, for torque, petrol=5 & diesel=2. i feel diesel engines have more torque.

[loving_alaap]

Unless we get a revolutionary battery, right now, CNG (subject to availabilty) followed by diesel is the best overall.

But yes, if you can afford (no worry about FE) there is nothing like petrol.

Have you heard in US & western countries, BMWs & Mreces sold with an diesel engine??